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);
        String line = sc.nextLine();

        String[] input = line.split(" ", 0);
        int N = Integer.valueOf(input[0]).intValue();
        int S = Integer.valueOf(input[1]).intValue();
        line = sc.nextLine();

        char[] c = line.toCharArray();

        if(c[S-1] == 'A'){
            c[S-1] = 'a';
        }else if(c[S-1] == 'B'){
            c[S-1] = 'b';
        }else if(c[S-1] == 'C'){
            c[S-1] = 'c';
        }

        for(int i = 0; i < N; i++) {
            System.out.print(c[i]);
        }
    }
}