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(){
    int S[4];
    int a;
    for(a=0;a<4;a++){scanf("%d\n",&S[a]);}
    if(12<10*S[0]+S[1]){
        if(10*S[2]+S[3]<=12){printf("YYMM");}
        else{printf("NA");}
    }
    else{if(10*S[2]+S[3]<=12)
    {printf("AMBIGUOUS");}
    else{printf("MMYY");}
    }
    return 0;
}