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 9.2.1) (judge verdict: Accepted)

#include <stdio.h>
#include <ctype.h>

int main(void){
    int n,k,i;
    char s[50];

    scanf("%d %d",&n,&k);
    scanf("%s",s);

    s[k - 1] = tolower(s[k - 1]);

    for (i = 0;i < n;i++){
        printf("%c",s[i]);

    }
    return 0;
}