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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
int main(void){
int N,K;
char S[55];
scanf("%d%d%s",&N,&K,S);
if(S[K-1]=='A'){
    S[K-1]='a';
}
else if(S[K-1]=='B'){
    S[K-1]='b';
}
else if(S[K-1]=='C'){
    S[K-1]='c';
}
printf("%s",S);
}