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 9.2.1) (judge verdict: Accepted)

#include<stdio.h>
#include<ctype.h>
int main(void)
{
    int N,K,i;
    char S[50];
  
    scanf("%d%d",&N,&K);
    scanf("%s",S);
  
    S[K-1]=tolower(S[K-1]);
  
    for(i=0;i<N;i++)
      printf("%c",S[i]);
        printf("\n");
  
    return 0;
}