#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using ll = long long;

int main(){
    int n; cin >> n;
    vector<int> p(n);
    for(auto &it: p){
        cin >> it;
        it--;
    }

    vector<int> a(n+1);
    for(int i = 0; i < n; i++) a[p[i]] = i;
    ll ans = 0;
    ll tot = -(a[0]+1);
    for(int i = 0; i < n-1; i++){
        tot += (a[i]+1)*2;
        tot -= a[i+1]+1;
        ans = max(ans, tot);
    }
    cout << ans << endl;
    return 0;
}