#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

#include <atcoder/fenwicktree>

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int n;
  cin >> n;
  vector<int> a(n);
  rep(i, n) cin >> a[i];
  vector<int> b(n);
  rep(i, n) b[a[i] - 1] = i;
  atcoder::fenwick_tree<ll> fw(n);
  ll ans = 0;
  rep(i, n) {
    ans += fw.sum(b[i], n);
    fw.add(b[i], 1);
  }
  cout << ans << '\n';
  return 0;
}