Problem:
Score : 200 points

Problem Statement

You are given a string S of length N consisting of lowercase English letters, and an integer K.
Print the string obtained by replacing every character in S that differs from the K-th character of S, with *.

Constraints

1 \leq K \leq N\leq 10

S is a string of length N consisting of lowercase English letters.

N and K are integers.

Input

Input is given from Standard Input in the following format:

N
S
K

Output

Print the string obtained by replacing every character in S that differs from the K-th character of S, with *.

Sample Input 1

5
error
2

Sample Output 1

*rr*r

The second character of S is r. When we replace every character in error that differs from r with *, we get the string *rr*r.

Sample Input 2

6
eleven
5

Sample Output 2

e*e*e*

Sample Input 3

9
education
7

Sample Output 3

******i**

Solution in Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.util.*;
import java.lang.Math;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    String s = sc.next();
    int k = sc.nextInt();
    char ans[] = new char[n];
    char key = s.charAt(k-1);
    char stack;
    
    for(int i = 0; i < n; i++){
      if(s.charAt(i) == key) ans[i] = key;
      else ans[i] = '*';
    } 
   	
  	for(int i = 0; i < n; i++) System.out.print(ans[i]);
    System.out.println();

  }
}