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){
    char s[50];
    int n,k;
    
    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;
    }
    
    printf("%s\n",s);
    
    return 0;
}