import functools @functools.lru_cache(maxsize=2) def fibonacci(n): if n < 3: return n else: return fibonacci(n - 2) + fibonacci(n - 1) def main(): ans = 0 i = 1 while True: val = fibonacci(i) if val > 40_00000: break if val % 2 == 0: ans += val i += 1 print(ans) main()