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 Scala (2.11.7) (judge verdict: Accepted)

object Main {
  val sc = new java.util.Scanner(System.in)

  def sin(n: Int): Seq[Int] = Seq.fill(n)(sc.nextInt())

  def main(args: Array[String]): Unit = {
    val n = sc.nextInt()
    sc.nextLine()
    val s = sc.nextLine()
    val k = sc.nextInt()

    println(
      s.foldLeft("")((b: String, c: Char) => b + (if (c == s(k - 1)) c else '*'))
    )
  }
}