Perfect number is a number equal to the sum of its divisors (other than the number itself). Semiperfect numbers called integers, which is one greater than or less than the sum of its divisors (eg, 2 or 4).
On the interval from a to b to find the sum of all of semiperfect numbers.
Two natural numbers а and b (1 ≤ a, b ≤ 2 000 000 000).
The answer to the problem.