Problem:
Score : 100 points

Problem Statement

You are given a string S of length N consisting of A, B and C, and an integer K which is between 1 and N (inclusive).
Print the string S after lowercasing the K-th character in it.

Constraints

1 ≤ N ≤ 50

1 ≤ K ≤ N

S is a string of length N consisting of A, B and C.

Input

Input is given from Standard Input in the following format:

N K
S

Output

Print the string S after lowercasing the K-th character in it.

Sample Input 1

3 1
ABC

Sample Output 1

aBC

Sample Input 2

4 3
CABA

Sample Output 2

CAbA

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
public class Main
{
    public static void main(String []args)
    {
        Scanner sc=new Scanner(System.in);
        int  n=sc.nextInt();
        int K=sc.nextInt();
        String S=sc.next();
        int p=S.charAt(K-1);
        char x=(char)(p+32);
System.out.print(S.substring(0,(K-1))+x+S.substring(K));
}
}