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 9.2.1) (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <iostream>
#include <string>
using namespace std;

int main(int argc, char* argv[]){

	int N, K;
	string S;
	cin >> N >> K;
	cin >> S;
	for(int i=0; i<S.size(); 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.c_str());
	return 0;
}