output_description: Print the string obtained by replacing every character in S that differs from
  the K-th character of S, with `*`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      S
      K
attempt: def getInt():
      return int(input())
  
  
  def getIntList():
      return [int(x) for x in input().split()]
  
  
  def zeros(n):
      return [0] * n
  
  
  class Debug:
      def __init__(self):
          self.debug = True
  
      def off(self):
          self.debug = False
  
      def dmp(self, x, cmt=""):
          if self.debug:
              if cmt != "":
                  w = cmt + ": " + str(x)
              else:
                  w = str(x)
              print(w)
          return x
  
  
  def prob():
      d = Debug()
      d.off()
      N = getInt()
      S = input()
      K = getInt()
      d.dmp((N, S, K), "N, S, K")
      keep = S[K - 1]
      newS = ""
      for c in S:
          if c == keep:
              newS += c
          else:
              newS += "*"
      return newS
  
  
  ans = prob()
  print(ans)
  
problem_description: 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 `*`.
samples: [{"input": "5\n    error\n    2", "output": "*rr*r\n    \n\nThe second character of S is `r`. When we replace every character in `error`\nthat differs from `r` with `*`, we get the string `*rr*r`.\n\n* * *"}, {"input": "6\n    eleven\n    5", "output": "e*e*e*\n    \n\n* * *"}, {"input": "9\n    education\n    7", "output": "******i**"}]