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 PHP7 (7.0.15) (judge verdict: Accepted)

<?php
$n=trim(fgets(STDIN));
$s=trim(fgets(STDIN));
$k=trim(fgets(STDIN));
$k=$s[$k-1];
$i=0;
while($i<$n){
  if($s[$i]==$k){
    echo $k;
  }else{
    echo "*";
  }
  ++$i;
}