题号：NC225177
时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 512 M，其他语言1024 M
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 512 M，其他语言1024 M
64bit IO Format: %lld
题目描述
xay has an array a of length n, he wants to know how many triples (i, j, k) satisfy 
。
输入描述:
The first line of input contains an integer n（）.
The second line of input contains n integers（
）.
输出描述:
Print a single integer, indicates the number of triples.