RT 修改：

题目描述

The Romans have attacked again. This time they are much more than the Persians but Shapur is ready to defeat them. He says: "A lion is never afraid of a hundred sheep".

Nevertheless Shapur has to find weaknesses in the Roman army to defeat them. So he gives the army a weakness number.

In Shapur's opinion the weakness of an army is equal to the number of triplets $i,j,k$ such that $i<j<k$ and $a_{i}>a_{j}>a_{k}$ where $a_x$ is the power of man standing at position $x$ . The Roman army has one special trait — powers of all the people in it are distinct.

Help Shapur find out how weak the Romans are.

输入格式

The first line of input contains a single number $n(3\le n\le10^6)$ — the number of men in Roman army. Next line contains $n$ different positive integers $a_i(1\le i\le n，1\le a_i \le10^9)$ — powers of men in the Roman army.

The Romans have attacked again. This time they are much more than the Persians but Shapur is ready to defeat them. He says: "A lion is never afraid of a hundred sheep".

Nevertheless Shapur has to find weaknesses in the Roman army to defeat them. So he gives the army a weakness number.

In Shapur's opinion the weakness of an army is equal to the number of triplets 
$i,j,k$ such that $i<j<k$ and $a_{i}>a_{j}>a_{k} $ where 
$a_x$
  is the power of man standing at position 
$x$ . The Roman army has one special trait — powers of all the people in it are distinct.


Help Shapur find out how weak the Romans are.

The first line of input contains a single number $n(3\le n\le10^6)$ — the number of men in Roman army.  Next line contains 
$n$ different positive integers $a_i(1\le i\le n，1\le a_i \le10^9)$ — powers of men in the Roman army.

此外建议在翻译中加上 “C/C++ 选手请使用 %I64d 标准输出 long long 型数据，而不是 %lld。”