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: Runtime Error)

#include<stdio.h>
int main(){
	char str[10];
	int a,b;
	scanf("%d %d",&a,&b);
	scanf("%s",str);
	if(str[b-1]>=97&&str[b-1]<=122){
      str[b-1]=str[b-1]-32;
	}
  	else{
	str[b-1]=str[b-1]+32;
	  }
	  printf("%s",str);
printf("\n");
return 0;
}