#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using vc = vector<char>;
using vvc = vector<vc>;
using pll = pair<ll, ll>;
using stkll = vector<pll>;
const ll INF = 1LL << 60;
const ll MOD = 1e9 + 7;
#define rep(i, n) for (ll i = 0; i < (n); i++)
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
#ifndef ONLINE_JUDGE
    #define debug(x) cerr << #x << ": " << x << endl;
#else
    #define debug(x)
#endif

/* SegTreeLazyProportional<X,M>(n,fx,fa,fm,fp,ex,em): モノイド(集合X, 二項演算fx,fa,fm,fp
   単位元ex,em)についてサイズnで構築
    set(int i, X x), build(): i番目の要素をxにセット。まとめてセグ木を構築する。O(n)
    update(i,x): i 番目の要素を x に更新。O(log(n))
    query(a,b):  [a,b) 全てにfxを作用させた値を取得。O(log(n))
*/
template <typename X, typename M>
struct SegTreeLazyProportional {
    using FX = function<X(X, X)>;
    using FA = function<X(X, M)>;
    using FM = function<M(M, M)>;
    using FP = function<M(M, int)>;
    int n;
    FX fx;
    FA fa;
    FM fm;
    FP fp;
    const X ex;
    const M em;
    vector<X> dat;
    vector<M> lazy;
    SegTreeLazyProportional(int n_, FX fx_, FA fa_, FM fm_, FP fp_, X ex_, M em_)
        : n(), fx(fx_), fa(fa_), fm(fm_), fp(fp_), ex(ex_), em(em_), dat(n_ * 4, ex), lazy(n_ * 4, em) {
        int x = 1;
        while (n_ > x) x *= 2;
        n = x;
    }

    void set(int i, X x) { dat[i + n - 1] = x; }
    void build() {
        for (int k = n - 2; k >= 0; k--) dat[k] = fx(dat[2 * k + 1], dat[2 * k + 2]);
    }

    /* lazy eval */
    void eval(int k, int len) {
        if (lazy[k] == em) return;  // 更新するものが無ければ終了
        if (k < n - 1) {            // 葉でなければ子に伝搬
            lazy[k * 2 + 1] = fm(lazy[k * 2 + 1], lazy[k]);
            lazy[k * 2 + 2] = fm(lazy[k * 2 + 2], lazy[k]);
        }
        // 自身を更新
        dat[k] = fa(dat[k], fp(lazy[k], len));
        lazy[k] = em;
    }

    void update(int a, int b, M x, int k, int l, int r) {
        eval(k, r - l);
        if (a <= l && r <= b) {  // 完全に内側の時
            lazy[k] = fm(lazy[k], x);
            eval(k, r - l);
        } else if (a < r && l < b) {                     // 一部区間が被る時
            update(a, b, x, k * 2 + 1, l, (l + r) / 2);  // 左の子
            update(a, b, x, k * 2 + 2, (l + r) / 2, r);  // 右の子
            dat[k] = fx(dat[k * 2 + 1], dat[k * 2 + 2]);
        }
    }
    void update(int a, int b, M x) { update(a, b, x, 0, 0, n); }

    X query_sub(int a, int b, int k, int l, int r) {
        eval(k, r - l);
        if (r <= a || b <= l) {  // 完全に外側の時
            return ex;
        } else if (a <= l && r <= b) {  // 完全に内側の時
            return dat[k];
        } else {  // 一部区間が被る時
            X vl = query_sub(a, b, k * 2 + 1, l, (l + r) / 2);
            X vr = query_sub(a, b, k * 2 + 2, (l + r) / 2, r);
            return fx(vl, vr);
        }
    }
    X query(int a, int b) { return query_sub(a, b, 0, 0, n); }

    /* debug */
    inline X operator[](int a) { return query(a, a + 1); }
    void print() {
        for (int i = 0; i < n; ++i) {
            cout << (*this)[i];
            if (i != n) cout << ",";
        }
        cout << endl;
    }
};

vector<int> lt[110000], rt[110000];

int main() {
    ll n;
    cin >> n;
    vll a(n), vec;
    rep(i, n) cin >> a[i], vec.push_back(a[i]);

    sort(vec.begin(), vec.end());
    map<ll, ll> zip, unzip;
    rep(i, n) zip[vec[i]] = i, unzip[i] = vec[i];

    using X = ll;
    using M = ll;
    auto fx = [](X x1, X x2) -> X { return x1 + x2 ; };
    auto fa = [](X x, M m) -> X { return x + m ; };
    auto fm = [](M m1, M m2) -> M { return m1 + m2 ; };
    auto fp = [](M m, int n) -> M {return n * m;};
    X ex = 0;
    M em = 0;
    SegTreeLazyProportional<X, M> seg(n, fx, fa, fm, fp, ex, em);

    ll ans = 0;
    rep(i, n) {
        ans += i - seg.query(0, zip[a[i]]+1);
        seg.update(zip[a[i]], zip[a[i]]+1, 1);
    }
    cout << ans << endl;
}


Measured memory_bytes: 48556