#include <bits/stdc++.h>
using namespace std;
int v[3005], inv = 0, n;
double sol;
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> v[i];
  for (int i = 1; i <= n; i++)
    for (int j = i + 1; j <= n; j++)
      if (v[i] > v[j]) inv++;
  sol = double(inv) - inv / 2 + (inv / 2) * 3.0;
  cout << fixed;
  cout << setprecision(6);
  cout << sol << "\n";
  return 0;
}
