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.Scanner;

public class Main {
	static Scanner sc = new Scanner(System.in);
	static int N;
	static int K;

	public static void main(String[] args) {
		N = sc.nextInt();
		K = sc.nextInt();

		char[] S = sc.next().toCharArray();
		if (S[K - 1] == 'A') {
			S[K - 1] = 'a';
		} else if (S[K - 1] == 'B') {
			S[K - 1] = 'b';
		} else if (S[K - 1] == 'C') {
			S[K - 1] = 'c';
		}

		System.out.println(S);
	}

}