function MOD(m: integer, n: integer): integer
  (* standard library function *)
  m - m/n * n




function divides(x: integer, n: integer): boolean
  (* returns true if x is a factor of n, for 0 < x <= n *)
  not MOD(n, x)




function count(bit: integer, n: integer): integer
  (* returns the number of time bit occurs as a digit in n. *)
  (* intended use is for bit in (0,1) and a binary n        *)
  if n < 10 then
     bit = n
  else
     if bit = MOD(n, 10)
        then 1 + count(bit, n/10)
        else count(bit, n/10)




function to_binary(m: integer): integer
  (* converts a decimal number n to its binary equivalent *)
  if n = 0
     then 0
     else 10 * to_binary(n/2) + MOD(n,2)




function apply_definition(binary_n: integer, n: integer): boolean
  (* computes the definition of is_special?, for binary number bin_n *)
  divides(count(true, binary_n), n)  and
  divides(count(false, binary_n), n)




function main(n: integer): integer
  apply_definition(to_binary(n), n)