fib := fn(n, a, b) {
  if (n == 0) {
    return a
  }
  if (n == 1) {
    return b
  }
  return fib(n - 1, b, a + b)
}

N := 35

if (len(args()) > 0) {
  N = int(args()[0])
}

println(fib(N, 0, 1))