let fib(n: i32): i32 = 
  if n <= 1 { n }
  else { fib(n - 1) + fib(n - 2) }

declare printf(s: cstring, ...): void

let main(): i32 = {
  for var i: i32 = x; i < 40; i = i+1 {
    printf("fib(%d) = %d\n", i, fib(i))
  }
  return 0
}