import random def is_prime(n): if n == 2: return True if n == 1 or n & 1 == 0: return False d = (n - 1) >> 1 while d & 1 == 0: d >>= 1 for k in range(100): a = random.randint(1, n - 1) t = d y = pow(a, t, n) while t != n - 1 and y != 1 and y != n - 1: y = (y * y) % n t <<= 1 if y != n - 1 and t & 1 == 0: return False return True if __name__ == '__main__': ans=1 for n in range(60): if is_prime(2**(n+1)+1): ans=ans*(2**(n+1)+1) print(ans/3) print(1)