题目描述
Problem Statement
Given are integers L and R. Find the number, modulo 10^9 + 7, of pairs of integers $(x, y) (L \leq x \leq y \leq R)$ such that the remainder when y is divided by x is equal to $y \text{ XOR } x$.
What is $\text{ XOR }$?
The XOR of integers A and $B, A \text{ XOR } B$, is defined as follows:
- When $A \text{ XOR } B$ is written in base two, the digit in the 2^k'$s place (k \geq 0)$ is 1 if either A or B, but not both, has 1 in the 2^k's place, and 0 otherwise.
For example$, 3 \text{ XOR } 5 = 6.$ (In base two: $011 \text{ XOR } 101 = 110.)$
Input
Input is given from Standard Input in the following format:
L R
Output
Print the number of pairs of integers $(x, y) (L \leq x \leq y \leq R)$ satisfying the condition, modulo 10^9 + 7.
Constraints
- $1 \leq L \leq R \leq 10^{18}$
Sample Input 1
2 3
Sample Output 1
3
Three pairs satisfy the condition: (2, 2), (2, 3), and (3, 3).
Sample Input 2
10 100
Sample Output 2
604
Sample Input 3
1 1000000000000000000
Sample Output 3
68038601
Be sure to compute the number modulo 10^9 + 7.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分