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 (Clang 10.0.0) (judge verdict: Accepted)

#include <stdio.h>
#include <ctype.h>
int a,b,i;
int main() {
 scanf("%d %d",&a,&b);
 
 char s[a];
 
 for(i=0;i<=a;i++)
  {
   scanf("%c",&s[i]);
  }
 
  
 for(i=0;i<=a;i++)
 {
   if(i==b)
   {
     s[i]=tolower(s[i]);
   }
 }
 
 for(i=0;i<=a;i++)
  {
   printf("%c",s[i]); 
  }
 

 return 0;
 
 }