Nukes has an integer that can be represented as the bitwise OR of one or more integers between A and B (inclusive). How many possible candidates of the value of Nukes's integer there are?

Constraints

• 1 ≤ A ≤ B < 2^{60}
• A and B are integers.

Input

The input is given from Standard Input in the following format:

A
B

Output

Print the number of possible candidates of the value of Nukes's integer.

Examples

Input

7
9

Output

4

Input

65
98

Output

63

Input

271828182845904523
314159265358979323

Output

68833183630578410

见题面

见题面