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 N;
  int i;
  cin >> N >> i;
string S;
  cin >> S;
  if ( S.at(i-1) == 'A'){
    S.at(i-1)='a';
  }
    if ( S.at(i-1) == 'B'){
    S.at(i-1)='b';
  }
    if ( S.at(i-1) == 'C'){
    S.at(i-1)='c';
  }
cout << S << endl;
}