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: Wrong Answer)

#include<stdio.h>

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

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

    if(s[k]=='A')
    {
        s[k]='a';
    }
    else if(s[k]=='B')
    {
        s[k]='b';
    }
    else
    {
        s[k]='c';
    }
    
    printf("%s",s);
    return 0;
}