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 n,k,i;
	char s[60];
	scanf("%d %d",&n,&k);
	scanf("%s",s);
	switch(s[k-1])
	{
		case 'A' : s[k-1]='a'; break;
		case 'B' : s[k-1]='b'; break;
		case 'C' : s[k-1]='c'; break;
	}
	printf("%s",s);
	return 0;
}