Problems

# Semiperfect number

# Semiperfect number

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*.

#### Input:

Two natural numbers **а** and **b** (**1** ≤ **a**, **b** ≤ **2 000 000 000**).

#### Output:

The answer to the problem.

Input example #1

2 5

Output example #1

6