#include <vector>
#include <cstdio>
#include <iostream>
#include <fstream>
/* #include "console.h" */
using namespace std;

long long count(vector<int> & a, int start, int l)
{
  if (l <= 1)
    return 0;

  int ll = l >> 1;
  int rl = l - ll;
  int rs = start + ll;


  long long left = count(a, start, ll);
  /* cout << "left = " << left << endl; */
  /* cout << "left array: "; */ 
  /* for (int i = start; i < start + ll; i++) cout << a[i] << ' '; */
  /* cout << endl; */

  long long right = count(a, rs, rl);
  /* cout << "right = " << right << endl; */
  /* cout << "right array: "; */ 
  /* for (int i = rs; i < start + l; i++) cout << a[i] << ' '; */
  /* cout << endl; */

  int i = start, j = rs;
  long long inv = 0;

  vector<int> b(l);
  int k = 0;
  while(i < rs && j < start + l)
  {
    if (a[i] > a[j])
    {
      b[k] = a[j];
      j++;
    }
    else{
      inv += j - rs;
      b[k] = a[i];
      i++;
    }
    k++;
  }

  while(i < rs)
  {
    inv += rl;
    b[k++] = a[i++];
  }
  while (j < start + l)
  {
    b[k++] = a[j++];
  }

  for (int c = start; c < start + l; c++)
    a[c] = b[c - start];

  return left + right + inv;

}

int main()
{
  /* ifstream fs("P1908_1.in"); */
  int n;
  cin >> n;
  /* fs >> n; */
  vector<int> a(n);
  for (int i = 0; i < n; i++)
  {
    cin >> a[i];
    /* fs >> a[i]; */
    /* scanf("%d", a[i]); */
  }
  cout << count(a, 0, n);

  return 0;
}