program main
  implicit none
  integer N, K, i
  character(10) s, v, sbit
  character(1) ref1, ref2
  read(*, *) N
  read(*, *) v
  read(*, *) K
  s = v(1:N)
  sbit = s
  sbit = trim(sbit)
  ref1 = s(K:K)
  do i = 1,N
    ref2 = s(i:i)
    if (ref1 /= ref2) then
      sbit(i:i) = '*'
    end if
  end do
  write(*,'(A)') sbit
end program main
