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.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Scanner;

public class Main {
	public static void main(final String[] args) {
		@SuppressWarnings("resource")
		final Scanner in = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
		final int N = in.nextInt();
		final int K = in.nextInt();
		final String S = in.next();
		String R = solve(S, K);
		System.out.println(R);
	}

	public static boolean isPossibleMonth(String m) {
		final int val = Integer.parseInt(m);
		return val <= 12 && val >= 1;
	}

	static String solve(final String S, final int K) {
		final char[] chars = S.toCharArray();
		chars[K - 1] = (char) (chars[K - 1] - 'A' + 'a');
		return new String(chars);
	}
}