let
  function odd(n:int):int =
     if (n = 0) then 0
     else if (n = 1) then 1
          else even(n-1)
  function even(n:int):int =
     if (n = 0) then 1
     else odd (n-1)
in
  if odd(5)
  then print("5 is odd\n")
  else print("5 is even\n")
end