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: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;

int main() {
  int N;
  int K;
  string str1;
  cin >> N >> K;
  cin >> str1;
  
  for (int i = 0; i < N; i++) {
    if (K-1 == i){
    if (str1.at(i) == 'A') {
    cout << "a" << endl;
  }
  if (str1.at(i) == 'a') {
    cout << "A" << endl;
  }
  if (str1.at(i) == 'B') {
    cout << "b" << endl;
  }
  if (str1.at(i) == 'b') {
    cout << "B" << endl;
  }
  if (str1.at(i) == 'C') {
    cout << "c" << endl;
  }
  if (str1.at(i) == 'c') {
    cout << "C" << endl;
  }
      
               }
    else{
      cout << str1.at(i) << endl;
        }
  }
}