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 C (GCC 5.4.1) (judge verdict: Accepted)

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
int main() {
	int num, num1;
	char str[50];
	scanf("%d %d", &num, &num1);
	
		
	
		scanf("%s", str);
	
	for (int i = 0; i < num; i++) {



		if (num1 -1== i) {
			if ('A'==str[i]) {
				str[i ] = 'a';
			}
			else if ('B'==str[i ]) {
				str[i] = 'b';
			}
			else if ('C'==str[i]) {
				str[i] = 'c';
			}

		}
	}
		
			printf("%s", str);
		
	}