if n is the product of all the integers from 5 to 20 , inclusive , what is the greatest integer k for which 2 ^ k is a factor of n ?
20 / 2 = 10 10 / 2 = 5 ans : 10 + 5 = 15 answer : e
add(add(add(add(add(add(add(const_1, const_3), const_1), 2), const_1), const_4), const_1), 2)