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;

    scanf("%d", &N);
    scanf("%d", &K);

    char str[N];

    scanf("%s", str);

    if(str[K-1] == 'A'){
        str[K - 1] = 'a';
    }else if(str[K-1] == 'B'){
        str[K - 1] = 'b';
    }else if(str[K-1] == 'C'){
        str[K - 1] = 'c';
    }

    printf("%s", str);

    return 0;
}