#include <bits/stdc++.h>
using namespace std;
inline long long gcd(long long x, long long y) { return x ? gcd(y % x, x) : y; }
const long long mod = 1e9 + 7;
inline signed rd() {
  signed ans = 0;
  char last = ' ', ch = getchar();
  while (!(ch >= '0' && ch <= '9')) last = ch, ch = getchar();
  while (ch >= '0' && ch <= '9') ans = ans * 10 + ch - '0', ch = getchar();
  if (last == '-') ans = -ans;
  return ans;
}
inline long long QPow(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % mod;
    a = a * a % mod;
    b >>= 1;
  }
  return ans;
}
inline long long QPow(long long a, long long b, const long long &mod) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % mod;
    a = a * a % mod;
    b >>= 1;
  }
  return ans;
}
long long exgcd(long long a, long long b, long long &x, long long &y) {
  long long d = a;
  if (b == 0)
    x = 1, y = 0;
  else {
    d = exgcd(b, a % b, y, x), y -= a / b * x;
  }
  return d;
}
const long double PI = 3.141592653589793115997963468544185161590576171875;
const long long maxn = 5002;
long long n;
long long arr[maxn];
signed main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  long long p, t, m, R;
  string str;
  cin >> n;
  for (long long i = 1; i <= n; i++) cin >> arr[i];
  long long tot = 0;
  for (long long i = 1; i <= n; i++)
    for (long long j = i + 1; j <= n; j++) tot += arr[i] > arr[j];
  long long flag = tot % 2;
  cout << fixed << setprecision(7) << double(tot / 2) * 4 + flag << endl;
  return 0;
}
