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 10.0.0) (judge verdict: Accepted)

#include <stdio.h>

int main(void) {
    int N,K;
    char str[90];
    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;
}