#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
template<class T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define SPEED \
ios_base::sync_with_stdio(0); \
cin.tie(NULL); \
cout.tie(NULL);
#define pb push_back
#define ins insert
#define fi first
#define se second
#define endl "\n"
#define ALL(x) x.begin(), x.end()
#define sz(x) x.size()
#define intt long long
const intt mod = 1e9 + 7;
const intt base = 31;
const intt inf = 1e9;
const intt mxN = 1e3 + 5;
const intt L = 21;
void solve() {
intt n;
cin >> n;
vector<intt> a(n);
for(intt i = 0; i < n; i++) {
cin >> a[i];
}
ordered_multiset<intt> mst, cmst;
for(intt i = 1; i < n; i++) {
mst.insert(a[i]);
}
cmst.insert(a[0]);
intt ans = 0;
for(intt i = 1; i < n - 1; i++) {
mst.erase(mst.find_by_order(mst.order_of_key(a[i])));
intt sol = cmst.order_of_key(a[i]);
intt sag = mst.order_of_key(a[i]);
ans += sol * sag;
cmst.insert(a[i]);
// cout << i << ": " << ans << endl;
}
cout << ans << endl;
}
signed main() {
SPEED;
intt tst = 1;
// cin >> tst;
while (tst--) {
solve();
}
}
