diff --git a/src/main/java/org/jugbd/marathon/day1/BiggestNumber.java b/src/main/java/org/jugbd/marathon/day1/BiggestNumber.java
new file mode 100644
index 0000000..2c9a15f
--- /dev/null
+++ b/src/main/java/org/jugbd/marathon/day1/BiggestNumber.java
@@ -0,0 +1,71 @@
+package org.jugbd.marathon.day1;
+
+
+
+public class BiggestNumber {
+	public static long findTheNextBiggerNumber(long n) {
+
+         int length=String.valueOf(n).length();
+		
+		int[] y=new int[length];
+		
+		long temp=n;
+		int i=0;
+		while(temp>0){
+			
+			y[i]=(int) (temp%10);
+			temp=temp/10;
+			i++;
+		}
+		
+		int[] arr=new int[length];
+		for( int m=0,k=length-1;m<n && k>=0;m++,k--){
+			
+			arr[k]=y[m];
+		}
+		
+		
+		
+		for(i=length-1;i>0;i--){
+			
+			if(arr[i]>arr[i-1]){
+				break;
+			}
+		}
+		
+		if(i==0){
+			return -1;
+		}
+		
+		int smallest1=arr[i-1];
+		int smallest2=arr[i];
+		int smlIndex=i;
+		
+		for(int j=i+1;j<length;j++){
+			if(arr[j]>smallest1 && arr[j]<smallest2){
+				smallest2=arr[j];
+				smlIndex=j;
+				
+			}
+		}
+		
+		  
+		
+		 temp=smallest1;
+		 arr[i-1]=smallest2;
+		 arr[smlIndex]=(int) temp;
+		 
+		
+		
+		Arrays.sort(arr,i,length);
+		
+		
+		 long ans=0;
+		 for(i=0;i<length;i++){
+			 ans=ans*10+arr[i];
+		 }
+		 
+		 
+		return ans;
+	}
+}