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)

#include <stdio.h>

int main(){
	char S[50],num;
	int N,K;
	scanf("%d%d",&N,&K);
	scanf("%s",S);
	num=S[K-1];
	switch(num){
		case 'A':
			S[K-1]='a';
			break;
		case 'B':
			S[K-1]='b';
			break;
		case 'C':
			S[K-1]='c';
			break;
		default:
			break;
	}	
	printf("%s\n",S);
	return 0;
}