Time Limit: 3000 MS Memory Limit: 65536 K

## Description

Your job is to calculate ¡Æ(S1 XOR S2 XOR ¡ XOR Sn) mod 1000000007, where Li <= Si <= Hi, 1 <= i <= n.
## Input

The first line of the input is an integer T (T <= 100), which stands for the number of test cases you need to solve.
Every test case begins with an integer n (1 <= n <= 100), and followed by n pairs of integers L1, H1, L2, H2, ¡,Ln, Hn (1<=Li<=Hi<=10^9, 1<=i<=n).
Every pair occupies a line.
## Output

For every test case, you should output "Case #k: " first, where k indicates the case number and starts at 1. Then output the answer.
See sample for more details.
## Sample Input

2
1
1 10
2
1 2
2 3
## Sample Output

Case #1: 55
Case #2: 6
## Hint

A bitwise XOR performs the logical XOR operation on each pair of corresponding bits.
The result in each position is 1 if the two bits are different, and 0 if they are the same.
For example: 0101(decimal 5) XOR 0011(decimal 3) = 0110(decimal 6).
## Source

The 9th UESTC Programming Contest Final