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 OCaml (4.02.3) (judge verdict: Runtime Error)

let solve n = 1

let _ =
  let n = Scanf.scanf "%d\n" (fun n -> n) in
  let s = Scanf.scanf "%s\n" (fun s -> s) in
  let k = Scanf.scanf "%d\n" (fun k -> k) in
  let c = String.get s k in
  for i = 0 to n - 1 do
    let c' = String.get s i in
    print_char @@ if c = c' then c else '*'
  done