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>
#include <string.h>
int main(){
	char s[1000];
	int n,k;

	scanf("%d",&n);
	scanf("%d",&k);

	scanf("%s",s);
	
	for(int i=0;i<n;i++){
		if(i == k-1){
			if(s[i] == 'A'){
				s[i] = 'a';
			}else if(s[i] == 'B'){
				s[i] = 'b';
			}else if(s[i] == 'C'){
				s[i] = 'c';
			}
 		}
	}	
	printf("%s\n",s);
}