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;
        char S[50];

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

        switch(S[K-1]){
                case 'A':
                        S[K-1] = 'a';
                        break;
                case 'B':
                        S[K-1] = 'b';
                        break;
                case 'C':
                        S[K-1] = 'c';
                        break;
                default:
                        break;
        }

        printf("%s",S);

}