Semiperfect number#2395

Semiperfect number

1 secondo

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A perfect number is a number equal to the sum of its divisors other than itself. Semiperfect numbers are natural numbers that are exactly one greater or one less than the sum of their divisors (for example, $2$ and $4$ ).

Find the sum of all semiperfect numbers in the interval from $a$ to $b$ .

Input

Two natural numbers $a$ and $b$ ( $1 \leq a, b \leq 2000000000$ 1 \le a, b \le 2\,000\,000\,000).

Output

Output the answer to the problem.

Esempi

Esempio 1

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1 \leq a, b \leq 2000000000