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 C (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

int main(){
  int n,k;
  char s[10];
  char ast;
  int i;
  scanf("%d",&n);
  scanf("%s",s);
  scanf("%d",&k);
  //printf("%d %d %s\n",n,k,s);
  ast = s[k-1];
  for(i = 0;i<n;++i){
    if(s[i] != ast){
      s[i] = '*';
    }
  }
  printf("%s\n",s);
  return 0;
}