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 <bits/stdc++.h>
 using namespace std; 
 int main() {
    int a, k;
    cin >> a >> k;
    string s;
    cin >> s;
    string res = "";
    for (int i = 0; i < a; i++) {
        if (i == k-1) {
            res = res + char(s[i]+32);
        }
        else {
            res = res + s[i];
        }
    }
    cout << res;

 }