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: Accepted)

#include <stdio.h>

int main(void) {
   
   int N,K;
   scanf("%d%d",&N,&K);
   
   char S[N+10];
   scanf("%s",S);
   
   if(S[K - 1] == 'A'){
      S[K - 1] = 'a';
   }
   else if(S[K - 1] == 'B') {
      S[K - 1] = 'b';
   }
   else {
      S[K - 1] = 'c';
   }
   
   printf("%s\n",S);
   
   
   return 0;
}