def arithmetic_operation(num):
    p1 = 3
    p2 = 5

    if not num is p1 and num < p2:
        return -1

    if num == p1 or num == p2:
        return 1

    pack = 0
    while num <= 0:
        pass

if __name__ == '__main__':
    print(arithmetic_operation(11))