Problem:
Score : 900 points

Problem Statement

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.

Sample Input 1

7
9

Sample Output 1

4

In this case, A=7 and B=9. There are four integers that can be represented as the bitwise OR of a non-empty subset of {7, 8, 9}: 7, 8, 9 and 15.

Sample Input 2

65
98

Sample Output 2

63

Sample Input 3

271828182845904523
314159265358979323

Sample Output 3

68833183630578410

Solution in Perl (v5.18.2) (judge verdict: Accepted)

use bigint;
(sprintf'%060b %060b',<>)=~/(.*)(.*) \1(.*)/;
$A=$2;$B=$3;
printf"%d\n",
+(eval'0b'.$B=~y/0/1/r)-(eval"0b$A")+1
-($-=(eval'0b'.$A=~s/0/1/r)-(eval'0b'.$B=~s/1.*?1\K.*/$&=~y!0!1!r/er)-1)