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(){
	int N;
	int K;
	scanf("%d",&N);
	scanf("%d",&K);
	char s[51];
	int i;
	char dummy;
	scanf("%c",&dummy);
	for(i=1;i<=N;i++){
		scanf("%c",&s[i]);
	}
	if(s[K]=='A'){
		s[K]='a';
	}else if(s[K]=='B'){
		s[K]='b';
	}else{
		s[K]='c';
	}
	for(i=1;i<=N;i++){
		printf("%c",s[i]);
	}
}