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 (Clang 3.8.0) (judge verdict: Accepted)

#include <stdio.h>
int main() {
  int N,K;
  char S[51];
  scanf("%d" "%d",&N,&K);
  scanf("%s\n",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;
}