# 2019-11-23 01:28:44(JST)

import sys

from string import ascii_lowercase as alphabet





def main():

    n, s, k = sys.stdin.read().split()

    n, k = list(map(int, [n, k]))



    c = s[k-1]

    for l in alphabet:

        if l != c:

            s = s.replace(l, '*')

    

    print(s)

    



if __name__ == '__main__':

    main()

# 2019-11-23 01:28:44(JST)

import sys



def main():

    n, s, k = sys.stdin.read().split()

    n, k = list(map(int, [n, k]))



    c = s[k-1]

    letters = set(s) - set(c)

    for l in letters:

        s = s.replace(l, '*')

    

    print(s)

    



if __name__ == '__main__':

    main()

# 2019-11-23 01:28:44(JST)
import sys
from string import ascii_lowercase as alphabet


def main():
    n, s, k = sys.stdin.read().split()
    n, k = list(map(int, [n, k]))
    c = s[k - 1]
    for l in alphabet:
        if l != c:
            s = s.replace(l, "*")
    print(s)


if __name__ == "__main__":
    main()

# 2019-11-23 01:28:44(JST)
import sys


def main():
    n, s, k = sys.stdin.read().split()
    n, k = list(map(int, [n, k]))
    c = s[k - 1]
    letters = set(s) - set(c)
    for l in letters:
        s = s.replace(l, "*")
    print(s)


if __name__ == "__main__":
    main()

-from string import ascii_lowercase as alphabet -    for l in alphabet: -        if l != c: -            s = s.replace(l, "*") +    letters = set(s) - set(c) +    for l in letters: +        s = s.replace(l, "*")