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 9.2.1) (judge verdict: Accepted)

#include <stdio.h>
int main(void) {
  int N,K;
  char str[100];
  scanf("%d %d",&N,&K);
  scanf("%s",str);
  if( str[K-1] =='A')
    str[K-1] = 'a';
  if( str[K-1] =='B')
    str[K-1] = 'b'; 
  if( str[K-1] =='C')
    str[K-1] = 'c'; 
  printf("%s\n",str);
  return 0;
}