#ifndef ONLINE_JUDGE
#define _GLIBCXX_DEBUG
#endif

#define _USE_MATH_DEFINES
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
//https://boostjp.github.io/tips/multiprec-int.html

#define YES cout<<"Yes\n"
#define NO cout<<"No\n"
#define YN {cout<<"Yes\n";}else{cout<<"No\n";}// if(a==b)YN;
#define NO2 cout<<"-1\n"

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define rrep(i, n) for (int i=int(n)-1; i>=0; --i)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()

template <class T> struct fenwick_tree {
    using U = T;

  public:
    fenwick_tree() : _n(0) {}
    fenwick_tree(int n) : _n(n), data(n) {}

    void add(int p, T x) {
        assert(0 <= p && p < _n);
        p++;
        while (p <= _n) {
            data[p - 1] += U(x);
            p += p & -p;
        }
    }

    T sum(int l, int r) {
        assert(0 <= l && l <= r && r <= _n);
        return sum(r) - sum(l);
    }

  private:
    int _n;
    std::vector<U> data;

    U sum(int r) {
        U s = 0;
        while (r > 0) {
            s += data[r - 1];
            r -= r & -r;
        }
        return s;
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N;
    cin >> N;
    vector<int> A(N);
    rep(i,N) cin >> A[i];
    vector<int> A_sort = A;
    sort(all(A_sort));
    A_sort.erase(unique(all(A_sort)), A_sort.end());
    vector<int> POS(N);
    rep(i,N) {
        POS[i] = lower_bound(all(A_sort), A[i]) - A_sort.begin();
    }
    
    ll ans = 0;
    fenwick_tree<int> BIT(N+1);
    for (int i=0; i<A.size()-1; ++i) {
        BIT.add(POS[i], 1);
        ans += BIT.sum(POS[i+1]+1,N+1);
    }
    cout << ans << endl;
}