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A15009. Jee, You See?

编程题 普及/提高-

题目描述

During their training for the ICPC competitions, team "Jee You See" stumbled upon a very basic counting problem. After many "Wrong answer" verdicts, they finally decided to give up and destroy turn-off the PC. Now they want your help in up-solving the problem.

You are given 4 integers $n$ , $l$ , $r$ , and $z$ . Count the number of arrays $a$ of length $n$ containing non-negative integers such that:

- $l\le a_1+a_2+\ldots+a_n\le r$ , and
- $a_1\oplus a_2 \oplus \ldots\oplus a_n=z$ , where $\oplus$ denotes the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) operation.

Since the answer can be large, print it modulo $10^9+7$ .

输入格式

The only line contains four integers $n$ , $l$ , $r$ , $z$ ( $1 \le n \le 1000$ , $1\le l\le r\le 10^{18}$ , $1\le z\le 10^{18}$ ).

输出格式

Print the number of arrays $a$ satisfying all requirements modulo $10^9+7$ .

输入输出样例

输入 #1
3 1 5 1
输出 #1
13
输入 #2
4 1 3 2
输出 #2
4
输入 #3
2 1 100000 15629
输出 #3
49152
输入 #4
100 56 89 66
输出 #4
981727503

说明/提示

The following arrays satisfy the conditions for the first sample:

- $[1, 0, 0]$ ;
- $[0, 1, 0]$ ;
- $[3, 2, 0]$ ;
- $[2, 3, 0]$ ;
- $[0, 0, 1]$ ;
- $[1, 1, 1]$ ;
- $[2, 2, 1]$ ;
- $[3, 0, 2]$ ;
- $[2, 1, 2]$ ;
- $[1, 2, 2]$ ;
- $[0, 3, 2]$ ;
- $[2, 0, 3]$ ;
- $[0, 2, 3]$ .

The following arrays satisfy the conditions for the second sample:

- $[2, 0, 0, 0]$ ;
- $[0, 2, 0, 0]$ ;
- $[0, 0, 2, 0]$ ;
- $[0, 0, 0, 2]$ .
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