#include using std::cin; using std::cout; const char endl = '\n'; const int N = 3005; int n, p[N], c[N], ans; int lowbit(int x) { return x & -x; } void add(int x, int y) { for (; x <= n; x += lowbit(x)) c[x] += y; } int sum(int x) { int res = 0; for (; x; x -= lowbit(x)) res += c[x]; return res; } int main() { std::ios::sync_with_stdio(false); cin.tie(nullptr); cin >> n; for (int i = 1; i <= n; i++) { cin >> p[i]; } for (int i = n; i; i--) { ans += sum(p[i] - 1); add(p[i], 1); } cout << (ans * 2 - ans % 2) << endl; return 0; }