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: Wrong Answer)

/*
* @Author Silviase(@silviasetitech)
* For ProCon
*/

import java.util.*;
import java.lang.*;
import java.math.*;

public class Main{    
    static int n;
    static int[] x = new int[n];
    static int[] y = new int[n];
    static int[] z = new int[n];
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String s = sc.next();
        int n = sc.nextInt();
        for (int i = 0; i < s.length(); i++) {
            if (i == n-1) {
                String a = s.substring(n-1, n);
                a = a.toLowerCase();
                System.out.print(a);
            }else{
                System.out.print(s.charAt(i));
            }
        }
        System.out.println("");

        sc.close();
    }

}