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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

public class Program{
    public static void Main(){
        
        var n = int.Parse(Console.ReadLine());
        string line = Console.ReadLine();
        var k = int.Parse(Console.ReadLine());
        
        var word = line[k - 1];
        char[] words = new char[n];
        for(var i = 0; i < n; i++){
            if(line[i] == word){
                words[i] = word;
            }else{
                words[i] = '*';
            }
        }
        Console.WriteLine("{0}",new string(words));
    }
}