diff --git a/.gitignore b/.gitignore
index 378eac2..5acb669 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 build
+.vscode
diff --git a/1_constants_variables_and_types/CMakeLists.txt b/1_constants_variables_and_types/CMakeLists.txt
new file mode 100644
index 0000000..22ef3d4
--- /dev/null
+++ b/1_constants_variables_and_types/CMakeLists.txt
@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.10)
+
+project(cvt)
+
+add_compile_options(-Wall -Wextra -pedantic -Werror)
+
+add_executable(cvt main.cpp)
diff --git a/1_constants_variables_and_types/main.cpp b/1_constants_variables_and_types/main.cpp
new file mode 100644
index 0000000..b5af414
--- /dev/null
+++ b/1_constants_variables_and_types/main.cpp
@@ -0,0 +1,376 @@
+#include <iostream>
+
+bool bglob{true};
+bool * pbglob{&bglob};
+bool & rbglob{bglob};
+static bool sbglob{false};
+const bool cbglob{false};
+const bool *pcbglob{&cbglob};
+const bool &rcbglob{cbglob};
+const static bool csbglob{true};
+
+char cglob{50};
+char * pcglob{&cglob};
+char & rcglob{cglob};
+static char scglob{'t'};
+const char ccglob{true};
+const char *pccglob{&ccglob};
+const char &rccglob{ccglob};
+const static char cscglob{'y'};
+
+int iglob{123};
+int * piglob{&iglob};
+int & riglob{iglob};
+static int siglob{234};
+const int ciglob{345};
+const int *pciglob{&ciglob};
+const int &rciglob{iglob};
+const static int csiglob{567};
+
+float fglob{1.23};
+float* pfglob{&fglob};
+float & rfglob{fglob};
+static float sfglob{12.3};
+const float cfglob{2.34};
+const float * pcfglob{&cfglob};
+const float & rcfglob{fglob};
+const static float csfglob{23.4};
+
+double dglob{3.45};
+double* pdglob{&dglob};
+double & rdglob{dglob};
+static double sdglob{34.5};
+const double cdglob{4.56};
+const double * pcdglob{&cdglob};
+const double & rcdglob{dglob};
+const static double csdglob{45.6};
+
+long lglob{123456789};
+long* plglob{&lglob};
+long & rlglob{lglob};
+static long slglob{987654321};
+const long clglob{456789123};
+const long * pclglob{&clglob};
+const long & rclglob{lglob};
+const static long cslglob{123789465};
+
+template<typename T>
+void print_variable_info(const T& var, const std::string& name = "") {
+  std::string prefix = (name.empty()) ? "" : ("[" + name + "] ");
+
+  std::cout << "\n";
+  std::cout << prefix << "Value: " << var << "\n";
+  std::cout << prefix << "Address: " << &var << "\n"; // Q: why it won't print address of var with type "char"? what is needed to do?
+  std::cout << prefix << "Type: " << typeid(var).name() << "\n";
+  std::cout << prefix << "Sizeof: " << sizeof(var) << std::endl;
+}
+
+int main()
+{
+
+  bool bloc{true};
+  bool* pbloc{&bloc};
+  bool & rbloc{bloc};
+  static bool sbloc{false};
+  const bool cbloc{true};
+  const bool *pcbloc{&cbloc};
+  const bool &rcbloc{cbloc};
+  const static bool csbloc{true};
+
+  char cloc{50};
+  char* pcloc{&cloc};
+  char & rcloc{cloc};
+  static char scloc{'t'};
+  const char ccloc{true};
+  const char *pccloc{&ccloc};
+  const char &rccloc{ccloc};
+  const static char cscloc{'y'};
+
+  int iloc{123};
+  int* piloc{&iloc};
+  int & riloc{iloc};
+  static int siloc{234};
+  const int ciloc{345};
+  const int *pciloc{&ciloc};
+  const int &rciloc{iloc};
+  const static int csiloc{567};
+
+  float floc{1.23};
+  float* pfloc{&floc};
+  float & rfloc{floc};
+  static float sfloc{12.3};
+  const float cfloc{2.34};
+  const float * pcfloc{&cfloc};
+  const float & rcfloc{floc};
+  const static float csfloc{23.4};
+
+  double dloc{3.45};
+  double* pdloc{&dloc};
+  double & rdloc{dloc};
+  static double sdloc{34.5};
+  const double cdloc{4.56};
+  const double * pcdloc{&cdloc};
+  const double & rcdloc{dloc};
+  const static double csdloc{45.6};
+
+  long lloc{123456789};
+  long* plloc{&lloc};
+  long & rlloc{lloc};
+  static long slloc{987654321};
+  const long clloc{456789123};
+  const long * pclloc{&clloc};
+  const long & rclloc{lloc};
+  const static long cslloc{123789465};
+      
+  print_variable_info<bool>(bglob,"bglob, bool global var");
+  print_variable_info<bool*>(pbglob,"pbglob, bool global pointer to bglob");
+  print_variable_info<bool>(rbglob,"rbglob, bool global ref to bglob");
+
+  print_variable_info< bool>(cbglob,"cbglob, bool const global var");
+  print_variable_info<const bool*>(pcbglob,"pcbglob, bool const global pointer to bglob");
+  print_variable_info< bool>(rcbglob,"rcbglob, bool const global ref to bglob");
+
+  print_variable_info<bool>(sbglob,"sbglob, bool static global var");
+  print_variable_info<bool>(csbglob,"csbglob, bool const static global var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n" ;
+
+  print_variable_info<char>(cglob,"cglob, char global var");
+  print_variable_info<char*>(pcglob,"pcglob, char global pointer to cglob");
+  print_variable_info<char>(rcglob,"rcglob, char global ref to cglob");
+
+  std::cout << "\n[cglob, char global var] Address: " <<static_cast<const void *>(&cglob) << "\n";
+  std::cout << "[pcglob, char global pointer to cglob] Value: " <<static_cast<const void *>(pcglob) << "\n";
+
+  print_variable_info<char>(ccglob,"ccglob, char const global var");
+  print_variable_info<const char*>(pccglob,"pccglob, char const global pointer to cglob");
+  print_variable_info<char>(rccglob,"rccglob, char const global ref to cglob");
+
+  std::cout << "\n[ccglob, char const global var] Address: " << static_cast<const void *>(&ccglob) << "\n";
+  std::cout << "[pccglob, char const global pointer to ccglob] Value: " << static_cast<const void *>(pccglob) << "\n";
+
+  print_variable_info<char>(scglob,"scglob, char static global var");
+  print_variable_info<char>(cscglob,"cscglob, char const static global var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+  print_variable_info<int>(iglob,"iglob, int global var");
+  print_variable_info<int*>(piglob,"piglob, int global pointer to iglob");
+  print_variable_info<int>(riglob,"riglob, int global ref to iglob");
+
+  print_variable_info<int>(ciglob,"ciglob, int const global var");
+  print_variable_info<const int*>(pciglob,"pciglob, int const global pointer to iglob");
+  print_variable_info<int>(rciglob,"rciglob, int const global ref to iglob");
+
+  print_variable_info<int>(siglob,"siglob, int static global var");
+  print_variable_info<int>(csiglob,"csiglob, int const static global var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+  print_variable_info<float>(fglob,"fglob, float global var");
+  print_variable_info<float*>(pfglob,"pfglob, float global pointer to fglob");
+  print_variable_info<float>(rfglob,"rfglob, float global ref to fglob");
+
+  print_variable_info<float>(cfglob,"cfglob, float const global var");
+  print_variable_info<const float*>(pcfglob,"pcfglob, float const global pointer to fglob");
+  print_variable_info<float>(rcfglob,"rcfglob, float const global ref to fglob");
+
+  print_variable_info<float>(sfglob,"sfglob, float static global var");
+  print_variable_info<float>(csfglob,"csfglob, float const static global var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+  print_variable_info<double>(dglob,"dglob, double global var");
+  print_variable_info<double*>(pdglob,"pdglob, double global pointer to dglob");
+  print_variable_info<double>(rdglob,"rdglob, double global ref to dglob");
+
+  print_variable_info<double>(cdglob,"cdglob, double const global var");
+  print_variable_info<const double*>(pcdglob,"pcdglob, double const global pointer to dglob");
+  print_variable_info<double>(rcdglob,"rcdglob, double const global ref to dglob");
+
+  print_variable_info<double>(sdglob,"sdglob, double static global var");
+  print_variable_info<double>(csdglob,"csdglob, double const static global var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+  print_variable_info<long>(lglob,"lglob, long global var");
+  print_variable_info<long*>(plglob,"plglob, long global pointer to lglob");
+  print_variable_info<long>(rlglob,"rlglob, long global ref to lglob");
+
+  print_variable_info<long>(clglob,"clglob, long const global var");
+  print_variable_info<const long*>(pclglob,"pclglob, long const global pointer to lglob");
+  print_variable_info<long>(rclglob,"rclglob, long const global ref to lglob");
+
+  print_variable_info<long>(slglob,"slglob, long static global var");
+  print_variable_info<long>(cslglob,"cslglob, long const static global var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+print_variable_info<bool>(bloc,"bloc, bool local var");
+  print_variable_info<bool*>(pbloc,"pbloc, bool local pointer to bloc");
+  print_variable_info<bool>(rbloc,"rbloc, bool local ref to bloc");
+
+  print_variable_info<bool>(cbloc,"cbloc, bool const local var");
+  print_variable_info<const bool*>(pcbloc,"pcbloc, bool const local pointer to bloc");
+  print_variable_info<bool>(rcbloc,"rcbloc, bool const local ref to bloc");
+
+  print_variable_info<bool>(sbloc,"sbloc, bool static local var");
+  print_variable_info<bool>(csbloc,"csbloc, bool const static local var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+  print_variable_info<char>(cloc,"cloc, char local var");
+  print_variable_info<char*>(pcloc,"pcloc, char local pointer to cloc");
+  print_variable_info<char>(rcloc,"rcloc, char local ref to cloc");
+
+  std::cout << "\n[cloc, char local var] Address: " <<static_cast<const void *>(&cloc) << "\n";
+  std::cout << "[pcloc, char local pointer to cloc] Value: " <<static_cast<const void *>(pcloc) << "\n";
+
+  print_variable_info<char>(ccloc,"ccloc, char const local var");
+  print_variable_info<const char*>(pccloc,"pccloc, char const local pointer to cloc");
+  print_variable_info<char>(rccloc,"rccloc, char const local ref to cloc");
+
+  std::cout << "\n[ccloc, char const local var] Address: " <<static_cast<const void *>(&ccloc) << "\n";
+  std::cout << "[pccloc, char const local pointer to cloc] Value: " <<static_cast<const void *>(pccloc) << "\n";
+
+  print_variable_info<char>(scloc,"scloc, char static local var");
+  print_variable_info<char>(cscloc,"cscloc, char const static local var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+  print_variable_info<int>(iloc,"iloc, int local var");
+  print_variable_info<int*>(piloc,"piloc, int local pointer to iloc");
+  print_variable_info<int>(riloc,"riloc, int local ref to iloc");
+
+  print_variable_info<int>(ciloc,"ciloc, int const local var");
+  print_variable_info<const int*>(pciloc,"pciloc, int const local pointer to iloc");
+  print_variable_info<int>(rciloc,"rciloc, int const local ref to iloc");
+
+  print_variable_info<int>(siloc,"siloc, int static local var");
+  print_variable_info<int>(csiloc,"csiloc, int const static local var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+  print_variable_info<float>(floc,"floc, float local var");
+  print_variable_info<float*>(pfloc,"pfloc, float local pointer to floc");
+  print_variable_info<float>(rfloc,"rfloc, float local ref to floc");
+
+  print_variable_info<float>(cfloc,"cfloc, float const local var");
+  print_variable_info<const float*>(pcfloc,"pcfloc, float const local pointer to floc");
+  print_variable_info<float>(rcfloc,"rcfloc, float const local ref to floc");
+
+  print_variable_info<float>(sfloc,"sfloc, float static local var");
+  print_variable_info<float>(csfloc,"csfloc, float const static local var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+  print_variable_info<double>(dloc,"dloc, double local var");
+  print_variable_info<double*>(pdloc,"pdloc, double local pointer to dloc");
+  print_variable_info<double>(rdloc,"rdloc, double local ref to dloc");
+
+  print_variable_info<double>(cdloc,"cdloc, double const local var");
+  print_variable_info<const double*>(pcdloc,"pcdloc, double const local pointer to dloc");
+  print_variable_info<double>(rcdloc,"rcdloc, double const local ref to dloc");
+
+  print_variable_info<double>(sdloc,"sdloc, double static local var");
+  print_variable_info<double>(csdloc,"csdloc, double const static local var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+  print_variable_info<long>(lloc,"lloc, long local var");
+  print_variable_info<long*>(plloc,"plloc, long local pointer to lloc");
+  print_variable_info<long>(rlloc,"rlloc, long local ref to lloc");
+
+  print_variable_info<long>(clloc,"clloc, long const local var");
+  print_variable_info<const long*>(pclloc,"pclloc, long const local pointer to lloc");
+  print_variable_info<long>(rclloc,"rclloc, long const local ref to lloc");
+
+  print_variable_info<long>(slloc,"slloc, long static local var");
+  print_variable_info<long>(cslloc,"cslloc, long const static local var");
+
+  std::cout << "---------------------------------------------------------------------" << "\n";
+
+    unsigned char ucloc{'k'};
+
+    iloc=floc;
+    std::cout << "iloc <- 12.34\n" << "iloc=" << iloc << "\n";
+    std::cout << "-------\n";
+    dloc=iloc;
+    std::cout << "dloc <- 12\n" << "dloc=" << dloc << "\n";
+    std::cout << "-------\n";
+    iloc=cloc;
+    std::cout << "iloc <- 'k'\n" << "iloc=" << iloc << "\n";
+    std::cout << "-------" << "\n";
+    iloc=1000;
+    cloc=iloc;
+    ucloc=iloc;
+    std::cout << "cloc <- 1000\n" << "cloc=" << (int)cloc << "\n";
+    std::cout << "ucloc <- 1000\n" << "ucloc=" << (int)ucloc << "\n";
+    std::cout << "---------------------------------------------------------------------\n\n";;
+
+    unsigned char * puchar{&ucloc};
+    std::cout << "*puchar <- ucloc \n" << "*puchar=" << int (*puchar) << "\n";
+    *puchar=*puchar +1;
+    std::cout << "increment *puchar \n" << "*puchar=" << int (*puchar) << " \nucloc=" << (int)ucloc << "\n";
+
+  std::cout << "---------------------------------------------------------------------\n";
+
+    auto adloc{345.567};
+
+    std::cout << "Variable adloc= " << adloc << "\n";
+    std::cout << "Type of adloc is " << typeid(adloc).name() << "\n";
+
+    //     To learn the most common mistakes and know how compilation errors look like try the next:
+    // - create two, global and local, variables with the same name;
+    // - change a value of a constant;
+    // - create a reference without assigning the value;
+    // - passing the address of a variable of a specific type to a pointer of a different type;
+    // - print a value of nullable pointer;
+    // - pass some value (for example, 0, 1, 2 ... whatever) to the pointer;
+    // - pass a value to a variable of a different type (for example, pass "some_string" to int variable).
+
+  std::cout << "---------------------------------------------------------------------" << std::endl;
+
+    std::cout << "Global iglob befor definition of local variable = " << iglob << "\n";
+    int iglob{2378};
+    std::cout << "iglob after definition 'int iglob{2378}' of local variable = " << iglob << "\n";
+    //the compiler doesn't generate any error. Local variable just shadow the global variable
+
+    //icglob=18;
+    //error: assignment of read-only variable ‘icglob’
+
+    //int &riglob_new;
+    //ERROR: ‘riglob_new’ declared as reference but not initialized
+
+       // unsigned int * uipointer = &iglob;
+    //error: invalid conversion from ‘int*’ to ‘unsigned int*’
+
+    //std::cout << endl << "---------------------------------------------------------------------" << endl;
+
+    //int * npointer{nullptr};
+    //There is no compilation error
+    // try{
+    //    std::cout << "Value of nullptr pointer = " << *npointer << endl; 
+    // }
+    // catch (...){
+    //     std::cout << "Error with nullptr pointer" << endl;
+    // }
+    //ERROR: Segmentation fault
+
+    //std::cout << endl << "---------------------------------------------------------------------" << endl;
+
+    //int * somepointer;
+
+    //somepointer=56;
+    //std::cout << "somepointer value = " << somepointer << ", value from pointer = " << *somepointer << endl; 
+    //error: invalid conversion from ‘int’ to ‘int*’ [-fpermissive]   
+    
+    ///std::cout << endl << "---------------------------------------------------------------------" << endl;
+    
+    //iglob="Some string.";
+    //ERROR: error: invalid conversion from ‘const char*’ to ‘int’ [-fpermissive]
+
+
+    std::cout << std::endl;
+    return 0;
+}
\ No newline at end of file
diff --git a/1_some_title/CMakeLists.txt b/1_some_title/CMakeLists.txt
deleted file mode 100644
index e69de29..0000000
diff --git a/2_another_title/CMakeLists.txt b/2_another_title/CMakeLists.txt
index e69de29..8b13789 100644
--- a/2_another_title/CMakeLists.txt
+++ b/2_another_title/CMakeLists.txt
@@ -0,0 +1 @@
+
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 55c0477..3e06409 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,7 @@
+cmake_minimum_required(VERSION 3.10)
+
 project(basecamp)
 
-add_subdirectory(1_some_title)
+add_subdirectory(1_constants_variables_and_types)
 add_subdirectory(2_another_title)
 # add_subdirectory(3_...)
diff --git a/README.md b/README.md
index c578785..7cf1928 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,3 @@
-BASECAMP FOLDER STRUCTURE
+## BASECAMP FOLDER STRUCTURE
+
+ - `1_constants_variables_and_types` - learning of behavior and memory allocation of constants, variables, types, pointers and references
\ No newline at end of file