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>
#include <string.h>
int main(void)
{
    int n,k,i;
    char s[11];
    scanf("%d%s%d", &n,s,&k);
    for(i=0; i<n; i++)
    {
        if(strncmp(&s[k-1], &s[i], 1)==0) printf("%c", s[i]);
        else printf("*");
    }
    return 0;
}