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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.PrintWriter;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        try (InputReader in = new InputReader(); PrintWriter out = new PrintWriter(System.out)) {
            new Main().solve(in, out);
            out.flush();
        }
    }

    void solve(InputReader in, PrintWriter out) {
        int n = in.nextInt();
        String s = in.next();
        int k = in.nextInt();

        char t = s.charAt(k - 1);
        out.println(s.replaceAll("[^" + String.valueOf(t) + "]", "*"));
    }
}

class InputReader implements AutoCloseable {
    private final Scanner sc = new Scanner(System.in);

    String next() {
        return this.sc.next();
    }

    int nextInt() {
        return Integer.parseInt(this.sc.next());
    }

    long nextLong() {
        return Long.parseLong(this.sc.next());
    }

    double nextDouble() {
        return Double.parseDouble(this.sc.next());
    }

    @Override
    public void close() {
        this.sc.close();
    }
}