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(){
	int a, b, i;
	char c[50];
	scanf("%d", &a);
	scanf("%d", &b);
  b-=1;
	for(i = 0;i<a;i++){
		scanf("%s", &c[i]);
	}
	if(c[b]=='A'){
		c[b]='a';
	}else if(c[b]=='B'){
		c[b]='b';
	}else{
		c[b]='c';
	}
	for(i = 0;i<a;i++){
		printf("%c", c[i]);
	}	
	return 0;
}