CF61E.Enemy is weak

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.

罗马人再次发动了进攻。这一次，他们的兵力远超波斯人，但沙普尔已做好击败他们的准备。他说道：“雄狮从不畏惧百只绵羊。”

然而，沙普尔必须找出罗马军队的弱点才能将其击败。因此，他为这支军队赋予了一个“弱点值”。

在沙普尔看来，一支军队的弱点值等于满足 $i < j < k$ 且 $a_i > a_j > a_k$ 的三元组 $(i, j, k)$ 的个数，其中 $a_x$ 表示位于位置 $x$ 的士兵的战力。罗马军队有一个特殊性质——所有士兵的战力互不相同。

请帮助沙普尔计算出罗马军队的弱点值。

The first line of input contains a single number n (3 ≤ n ≤ 106) — the number of men in Roman army. Next line contains n different positive integers a__i (1 ≤ i ≤ n, 1 ≤ a__i ≤ 109) — powers of men in the Roman army.

输入的第一行包含一个整数 $n$（$3 \leq n \leq 10^6$）—— 罗马军队中士兵的人数。
第二行包含 $n$ 个互不相同的正整数 $a_i$（$1 \leq i \leq n$，$1 \leq a_i \leq 10^9$）—— 罗马军队中各士兵的战斗力。

A single integer number, the weakness of the Roman army.

Please, do not use %lld specificator to read or write 64-bit integers in C++. It is preffered to use cout (also you may use %I64d).

罗马军队的弱点值（一个整数）。

请注意，在 C++ 中读取或写入 64 位整数时，请勿使用 %lld 格式说明符。推荐使用 cout（您也可使用 %I64d）。