diff --git a/README.md b/README.md
index fcf3f057..6c767d97 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,10 @@
 
 ## 과제 제출 과정
 * [과제 제출 방법](https://github.com/next-step/nextstep-docs/tree/master/ent-precourse)
+
+<기능 목록>
+
+1. 유저 인풋 기능
+2. 컴퓨터 난수 생성 기능
+3. 스트라이크/볼 체크 기능
+4. 게임 재시작 기능
\ No newline at end of file
diff --git a/src/main/java/Checker.java b/src/main/java/Checker.java
new file mode 100644
index 00000000..75ed3d10
--- /dev/null
+++ b/src/main/java/Checker.java
@@ -0,0 +1,41 @@
+public class Checker {
+    private int strike_arr[];
+    private int strike;
+    private boolean isex[];
+    private int ball;
+    private Opponent OP;
+
+    public Checker(Opponent OP_in){
+        strike_arr = new int[]{0,0,0};
+        isex = new boolean[]{false,false,false,false,false,false,false,false,false,false};
+        strike = 0;
+        ball = 0;
+        OP = OP_in;
+    }
+    public void compare(int user_input, int opp_number){
+        check_strike(user_input, opp_number);
+        check_ball(user_input);
+    }
+    public void check_strike(int user_input, int opp_number){
+        if(get100number(user_input) == get100number(opp_number)) strike_arr[0] = 1;
+        if(get10number(user_input) == get10number(opp_number)) strike_arr[1] = 1;
+        if(get1number(user_input) == get1number(opp_number)) strike_arr[2] = 1;
+        strike = strike_arr[0] + strike_arr[1] + strike_arr[2];
+    }
+    public void check_ball(int user_input){
+        if(strike_arr[0]==0 && OP.getintdict()[get100number(user_input)]) ball++;
+        if(strike_arr[1]==0 && OP.getintdict()[get10number(user_input)]) ball++;
+        if(strike_arr[2]==0 && OP.getintdict()[get1number(user_input)]) ball++;
+    }
+    public int get100number(int a){
+        return a / 100;
+    }
+    public int get10number(int a){
+        return a % 100 / 10;
+    }
+    public int get1number(int a){
+        return a % 10;
+    }
+    public int getStrike(){return strike;}
+    public int getBall(){return ball;}
+}
diff --git a/src/main/java/IOsys.java b/src/main/java/IOsys.java
new file mode 100644
index 00000000..a4018e6a
--- /dev/null
+++ b/src/main/java/IOsys.java
@@ -0,0 +1,37 @@
+import java.util.Scanner;
+
+public class IOsys {
+    private Scanner sc;
+
+    public IOsys(){
+        sc = new Scanner(System.in);
+    }
+    public int userIn(){
+        System.out.print("숫자를 입력해주세요: ");
+        int userinput = sc.nextInt();
+        while(userinput < 100 || 1000 <= userinput || check_dup(userinput)){
+            System.out.println("불가능한 입력입니다.");
+            System.out.print("숫자를 입력해주세요: ");
+            userinput = sc.nextInt();
+        }
+        return userinput;
+    }
+
+    public boolean check_dup(int userinput){
+        return userinput/100 == userinput%10 || userinput/100 == userinput%100/10 || userinput%10 == userinput%100/10;
+    }
+
+    public void print_result(Checker C){
+        if(C.getStrike()!= 0) System.out.printf("%d스트라이크 ", C.getStrike());
+        if(C.getBall() != 0) System.out.printf("%d볼 ", C.getBall());
+        if(C.getBall() + C.getStrike() == 0) System.out.printf("낫싱");
+        System.out.println();
+    }
+    public int nextgame(){
+        System.out.println("3개의 숫자를 모두 맞히셨습니다! 게임 종료");
+        System.out.println("게임을 새로 시작하려면 1, 종료하려면 2를 입력하세요.");
+        int ContinueFlag = sc.nextInt();
+
+        return ContinueFlag;
+    }
+}
diff --git a/src/main/java/Main.java b/src/main/java/Main.java
new file mode 100644
index 00000000..19bb8143
--- /dev/null
+++ b/src/main/java/Main.java
@@ -0,0 +1,6 @@
+public class Main {
+    public static void main(String[] args) {
+        game g = new game();
+        g.game_start();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/Opponent.java b/src/main/java/Opponent.java
new file mode 100644
index 00000000..8b0a7499
--- /dev/null
+++ b/src/main/java/Opponent.java
@@ -0,0 +1,36 @@
+import java.util.Random;
+
+public class Opponent {
+    private int Random_Int;
+    private boolean int_dict[];// if 1 exists, int_dict[1] = true
+
+    public Opponent(){
+        Random_Int = 0;
+        int_dict = new boolean[]{false,false,false,false,false,false,false,false,false,false};
+    }
+    public void generate_random_int(){
+        Random random = new Random();
+
+        int cur = random.nextInt(10);
+
+        while(cur == 0) cur = random.nextInt(10);
+        Random_Int += cur*100;
+        cur = check_pre(0, cur, random);
+        Random_Int += cur*10;
+        Random_Int += check_pre(Random_Int/100, cur, random);
+        init_int_dict();
+    }
+    public void init_int_dict(){
+        int_dict[Random_Int/100] = true;
+        int_dict[Random_Int%100/10] = true;
+        int_dict[Random_Int%10] = true;
+    }
+    public int getRandom_Int() {return this.Random_Int;}
+    public void setRandom_Int(int a) {this.Random_Int = a;}
+    public int check_pre(int pprevious, int previous, Random r){
+        int temp = previous;
+        while(temp == previous || temp == pprevious) temp = r.nextInt(10);
+        return temp;
+    }
+    public boolean[] getintdict(){return this.int_dict;}
+}
\ No newline at end of file
diff --git a/src/main/java/game.java b/src/main/java/game.java
new file mode 100644
index 00000000..f249c9e4
--- /dev/null
+++ b/src/main/java/game.java
@@ -0,0 +1,35 @@
+import com.sun.source.tree.ContinueTree;
+
+public class game {
+    private IOsys IO;
+    private int Continue_Flag;
+    private int strike_num;
+    public game(){
+        Continue_Flag = 1;
+        strike_num = 0;
+        IO = new IOsys();
+    }
+    public void game_start(){
+        while(Continue_Flag == 1){
+            Opponent OP = new Opponent();
+            OP.generate_random_int();
+
+            strike_num = 0;
+
+            play_one_game(OP);
+
+            Continue_Flag = IO.nextgame();
+        }
+    }
+    public void play_one_game(Opponent OP){
+        while(strike_num != 3) {
+            int userinput = IO.userIn();
+
+            Checker chk = new Checker(OP);
+            chk.compare(userinput, OP.getRandom_Int());
+            IO.print_result(chk);
+
+            strike_num = chk.getStrike();
+        }
+    }
+}
diff --git a/untitled/build.gradle b/untitled/build.gradle
new file mode 100644
index 00000000..3cae2d72
--- /dev/null
+++ b/untitled/build.gradle
@@ -0,0 +1,19 @@
+plugins {
+    id 'java'
+}
+
+group 'org.example'
+version '1.0-SNAPSHOT'
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.1'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.1'
+}
+
+test {
+    useJUnitPlatform()
+}
\ No newline at end of file
diff --git a/untitled/gradle/wrapper/gradle-wrapper.jar b/untitled/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 00000000..249e5832
Binary files /dev/null and b/untitled/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/untitled/gradle/wrapper/gradle-wrapper.properties b/untitled/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 00000000..ae04661e
--- /dev/null
+++ b/untitled/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.5.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/untitled/gradlew b/untitled/gradlew
new file mode 100755
index 00000000..a69d9cb6
--- /dev/null
+++ b/untitled/gradlew
@@ -0,0 +1,240 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
diff --git a/untitled/gradlew.bat b/untitled/gradlew.bat
new file mode 100644
index 00000000..53a6b238
--- /dev/null
+++ b/untitled/gradlew.bat
@@ -0,0 +1,91 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/untitled/settings.gradle b/untitled/settings.gradle
new file mode 100644
index 00000000..cc6146c6
--- /dev/null
+++ b/untitled/settings.gradle
@@ -0,0 +1,2 @@
+rootProject.name = 'untitled'
+
diff --git a/untitled/src/main/java/org/example/Main.java b/untitled/src/main/java/org/example/Main.java
new file mode 100644
index 00000000..407f157b
--- /dev/null
+++ b/untitled/src/main/java/org/example/Main.java
@@ -0,0 +1,7 @@
+package org.example;
+
+public class Main {
+    public static void main(String[] args) {
+        System.out.println("Hello world!");
+    }
+}
\ No newline at end of file