Sub Main
  n = 1
  TextWindow.WriteLine("Вычисление числа Фибоначчи")
  TextWindow.Write("Введите максимальное число: ")
  n = TextWindow.ReadNumber()
  Stack.PushValue("Heap", n)
  Stack.PushValue("Heap", n)
  Fibonacci()
  ret = Stack.PopValue("Heap")
  n = Stack.PopValue("Heap")
  TextWindow.WriteLine("Fibonacci(" + n + ") = " + ret)
  TextWindow.Read()
EndSub

sub Fibonacci
  n = Stack.PopValue("Heap")
  if (n = 0) then
    Stack.PushValue("Heap", 0)
  elseif (n = 1) then
    Stack.PushValue("Heap", 1)
  else
    Stack.PushValue("Heap", n)
    Stack.PushValue("Heap", n - 1)
    Fibonacci()
    ret = Stack.PopValue("Heap")
    n = Stack.PopValue("Heap")
    Stack.PushValue("Heap", ret)
    Stack.PushValue("Heap", n - 2)
    Fibonacci()
    Stack.PushValue("Heap", Stack.PopValue("Heap") + Stack.PopValue("Heap"))
  endif
endsub

Main()