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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<iostream>
#include<string>
#include<algorithm>	
#include<cmath>
using namespace std;
int main() {
	int n, a; string s; cin >> n >> a >> s;
	for (int h = 0; h < n; h++) {
		if (h == a - 1 && s[h] == 'A') { cout << 'a'; }
		else if (h == a - 1 && s[h] == 'B') { cout << 'b'; }
		else if (h == a - 1 && s[h] == 'C') { cout << 'c'; }
		else {
			cout << s[h];
		}
	}
	cout << endl;
	cin >> n;
}