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 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>

int main(void){
  
  int N;
  int K;
  char S[N];

  scanf("%d %d",&N,&K);
  
  fgets(S,N,stdin);
  
  for(int i = 0;i < N;++i){
    if(S[K] == 'A'){
    puts("a");
    }
    else if(S[K] == 'B'){
    puts("b");
    }
    else if(S[K] == 'C'){
    puts("c");
    }
    else{
    printf("%c",S[i]);
    }   
  }
  return 0;
  }