/* -*- coding: utf-8 -*-
 *
 * 3469.cc:  No.3469 繧ｸ繝｣繝・ず邨先棡縺ｮ騾・ｻ｢謨ｰ - yukicoder
 */

#include<cstdio>
#include<vector>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 200000;

/* typedef */

using ll = long long;

template <typename T>
struct SegTreeSum {
  int e2;
  vector<T> nodes;
  T defv;
  SegTreeSum() {}

  void init(int n, T _defv) {
    defv = _defv;
    for (e2 = 1; e2 < n; e2 <<= 1);
    nodes.assign(e2 * 2, defv);
  }

  T &geti(int i) { return nodes[e2 - 1 + i]; }
  void seti(int i, T v) { geti(i) = v; }

  void setall() {
    for (int j = e2 - 2; j >= 0; j--)
      nodes[j] = nodes[j * 2 + 1] + nodes[j * 2 + 2];
  }

  void set(int i, T v) {
    int j = e2 - 1 + i;
    nodes[j] = v;
    while (j > 0) {
      j = (j - 1) / 2;
      nodes[j] = nodes[j * 2 + 1] + nodes[j * 2 + 2];
    }
  }

  T sum_range(int r0, int r1, int k, int i0, int i1) {
    if (r1 <= i0 || i1 <= r0) return defv;
    if (r0 <= i0 && i1 <= r1) return nodes[k];

    int im = (i0 + i1) / 2;
    T v0 = sum_range(r0, r1, k * 2 + 1, i0, im);
    T v1 = sum_range(r0, r1, k * 2 + 2, im, i1);
    return v0 + v1;
  }
  T sum_range(int r0, int r1) { return sum_range(r0, r1, 0, 0, e2); }
};

/* global variables */

int as[MAX_N], uas[MAX_N];
SegTreeSum<int> st;

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", as + i);

  copy(as, as + n, uas);
  sort(uas, uas + n);
  int m = unique(uas, uas + n) - uas;

  ll sum = 0;
  st.init(n, 0);
  for (int i = 0; i < n; i++) {
    int ai = lower_bound(uas, uas + m, as[i]) - uas;
    sum += i - st.sum_range(0, ai + 1);
    st.set(ai, st.geti(ai) + 1);
  }

  printf("%lld\n", sum);
  
  return 0;
}