the unit digit in the product ( 784 x 618 x 917 x 463 ) is
"unit digit in the given product = unit digit in ( 4 x 8 x 7 x 3 ) = 2 answer is a"
subtract(multiply(multiply(multiply(784, 618), 917), 463), subtract(multiply(multiply(multiply(784, 618), 917), 463), add(const_4, const_4)))