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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"fmt"
	"io"
	"os"
)

func solve(w io.Writer, r io.Reader) {
	var N, K int
	var S string
	fmt.Fscan(r, &N, &S, &K)

	t := S[K-1]
	for i := 0; i < len(S); i++ {
		if S[i] == t {
			fmt.Fprintf(w, "%c", t)
		} else {
			fmt.Fprint(w, "*")
		}
	}
	fmt.Fprint(w, "\n")
}

func main() {
	solve(os.Stdout, os.Stdin)
}