#include <bits/stdc++.h> typedef long long ll; using namespace std; const int NMAX = 3e5; int aib[NMAX + 5]; int n; void update (int pos, const int &val) { for (; pos <= n; pos += pos & -pos) aib[pos] += val; } int query (int pos) { int ret = 0; for (; pos; pos -= pos & -pos) ret += aib[pos]; return ret; } ll a[NMAX + 5]; ll b[NMAX + 5]; ll ans[NMAX + 5]; int main() { cin >> n; for (int i=1; i<=n; i++) { cin >> a[i]; b[i] = a[i]; } sort (b+1, b+n+1); for (int i=1; i<=n; i++) { a[i] = lower_bound(b+1, b+n+1, a[i]) - (b + 1) + 1; } for (int i=1; i<=n; i++) { ans[i] = query(a[i] - 1); update(a[i], +1); } memset(aib, 0, sizeof(aib)); for (int i=n; i>0; i--) { ans[i] *= query(a[i] - 1); update(a[i], +1); } ll sum = 0; for (int i=1; i<=n; i++) sum += ans[i]; cout << sum; return 0; }