题号：NC52856
时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 32 M，其他语言64 M
Special Judge, 64bit IO Format: %lld
时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 32 M，其他语言64 M
Special Judge, 64bit IO Format: %lld
题目描述
Given n integers 
, Bobo knows how to compute the *sum of triples* 
It follows that%5E3%20-%203%20(%5Csum_%7B1%20%5Cleq%20i%20%5Cleq%20n%7D%20a_i%5E2)(%5Csum_%7B1%20%5Cleq%20i%20%5Cleq%20n%7D%20a_i)%20%2B%202(%5Csum_%7B1%20%5Cleq%20i%20%5Cleq%20n%7D%20a_i%5E3)%7D%7B6%7D.)
Bobo would like to compute the *sum of quadrangles*%5Cbmod%20(10%5E9%2B7).)
It follows that
Bobo would like to compute the *sum of quadrangles*
输入描述:
The input contains zero or more test cases and is terminated by end-of-file. For each test case,
The first line contains an integer n.
The second line contains n integers
*
*
* The number of tests cases does not exceed 10.
输出描述:
For each case, output an integer which denotes the result.