#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 1, MOD = 998244353;
typedef long long ll;
ll n,a[N],t[N * 4];
vector<ll> v;
void cl(){
for(int i = 1;i <= n * 4;i++){
t[i] =0;
}
}
void upd(int pos,int v = 1,int tl =1,int tr = n){
t[v]++;
if(tl ==tr) return;
int tm = (tl + tr) >> 1;
if(pos <= tm) upd(pos,v+v,tl,tm);
else upd(pos,v+v+1,tm+1,tr);
}
ll get(int l,int r,int v = 1,int tl = 1,int tr =n){
if(l > r || tl > r || l > tr) return 0;
if(tl >= l && tr <= r) return t[v];
int tm = (tl + tr) >> 1;
return get(l,r,v+v,tl,tm) + get(l,r,v+v+1,tm+1,tr);
}
ll l[N],res = 0;
void test(){
cin >> n;
for(int i = 1;i <= n;i++){
cin >> a[i];
v.push_back(a[i]);
}
sort(v.begin(),v.end());
for(int i = 1;i <= n;i++){
a[i] = (lower_bound(v.begin(),v.end(),a[i]) - v.begin()) + 1;
l[i] = get(1,a[i] - 1);
upd(a[i]);
}
cl();
for(int i = n;i >= 1;i--){
// cout << get(a[i] + 1,n) << '\n';
res += l[i] * get(1,a[i] - 1);
upd(a[i]);
}
cout << res;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int T = 1;//cin >> T;
while (T--) test();
}
