#include <bits/stdc++.h>
#define rep(i, l, r) for (int i = (l); i < (r); i++)
using namespace std;

typedef long long ll;

int main() {
    ll N;
    cin >> N;
    vector<int> P(N), Q(N);
    rep(i, 0, N) {
        cin >> P[i];
        Q[P[i] - 1] = i + 1;
    }
    if (N == 1) {
        cout << 0 << endl;
        return 0;
    }
    if (N == 2) {
        if (P[0] == 1) cout << 0 << endl;
        else cout << 1 << endl;
        return 0;
    }
    ll t = N * (N + 1) / 2, ans = 0;
    //cout << ans << endl;
    rep(i, 0, N) {
        ans = max(ans, t - 2 * Q[N - 1 - i]);
        t -= Q[N - 1 - i];
        //cout << i << " " << ans << endl;
    }
    cout << ans << endl;
}