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(){
char s[51];
int n,k;
scanf("%d %d",&n,&k);

scanf("%s",&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);

return 0;
}