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


class Program
{


    static void Main(string[] args)
    {

		char[] cs = new char[] { ' ' };
		//char[] cs = new char[] { ' ', ',' };

        //int val = int.Parse(Console.ReadLine());
        //int[] vals = parseAry(Console.ReadLine().Split(cs));
        //string str = Console.ReadLine();
        //string[] strs = Console.ReadLine().Split(cs);

        //string res="";
        //int res = 0; ;
        //int t = int.Parse(Console.ReadLine());
        //string str = Console.ReadLine();
        //int[] vals = parseAry(Console.ReadLine().Split(cs));
        //int n = int.Parse(Console.ReadLine());
		//string res="";
		string res = "";
		int n = int.Parse(Console.ReadLine());
		string str = Console.ReadLine();
		int k = int.Parse(Console.ReadLine());

		for ( int i = 0; i < str.Length; i++ ) {
			if ( str[i] == str[k-1] ) { res += str[k-1].ToString(); ; } else { res += "*"; }
		}
		
			Console.WriteLine(res);


        return;
    }

    //　String[]  ----->  int[]
    static int[] parseAry(string[] str)
    {
        int[] nums = new int[str.Length];
        for (int i = 0; i < str.Length; i++) { nums[i] = int.Parse(str[i]); }
        return nums;
    }
    //　String[]  ----->  long[]
    static long[] parseAryL(string[] str)
    {
        long[] nums = new long[str.Length];
        for (int i = 0; i < str.Length; i++) { nums[i] = long.Parse(str[i]); }
        return nums;
    }


    //文字列を1文字ずつString[]に入れる
    static string[] strAry(String str)
    {
        string[] re = new string[str.Length];
        for (int i = 0; i < str.Length; i++) { re[i] = str[i].ToString(); }
        return re;
    }

}