let solve n = 1

let _ =
  let n = Scanf.scanf "%d\n" (fun n -> n) in
  let s = Scanf.scanf "%s\n" (fun s -> s) in
  let k = Scanf.scanf "%d\n" (fun k -> k) in
  let c = String.get s (k-1) in
  let s' = ref "" in
  for i = 0 to n - 1 do
    let c' = String.get s i in
    s' := !s' ^ (if c = c' then String.make 1 c' else "*")
  done;
  print_string !s'
