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: Runtime Error)

import java.util.Scanner;

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[] = new String[N];
		if (N >= 1 && N <= 50 && K >= 1 && K <= N) {
			for (int i = 0; i < N; i++) {
				S[i] = sc.next();
				if (i == K - 1) {
					S[i] = S[i].toLowerCase();
				}
			}
			for (int i = 0; i < N; i++) {
				System.out.print(S[i]);
			}
		}
	}
}