def square(number):
    grains: int = 1
    if (number <= 0) or (number > 64):
        raise ValueError("square must be between 1 and 64")
    for _ in range(1, number):
        grains *= 2
    return grains


def total():
    total_grains: int = 0
    for square_number in range(1, 65):
        total_grains += square(square_number)
    return total_grains