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>
#include<stdlib.h>
#include<string.h>

#define MAX(p,q) (p>q)?p:q
#define MIN(p,q) (p<q)?p:q

#define REP(i,n) for(i=0;i<n;i++)

int main(void)
{
  int n,k;
  scanf("%d%d",&n,&k);
  char s[n+1];
  scanf("%s",s);
  s[k-1] = s[k-1] + 32;
  printf("%s",s);
  return 0;
}