import std.stdio, std.array, std.string, std.conv, std.algorithm;
import std.typecons, std.range, std.random, std.math, std.container;
import std.numeric, std.bigint, core.bitop;

immutable long MOD = 10^^9 + 7;

void main() {
    auto N = readln.chomp.to!int;
    auto A = readln.split.map!(x => x.to!int-1).array;
    auto B = new int[](N);
    foreach (i; 0..N) B[A[i]] = i;

    long ans = 0;
    long ans2 = 0;

    foreach (i; 0..N) if (A[i] != N-1) ans += i + 1; else ans -= i + 1;
    ans2 = ans;

    foreach_reverse (i; 1..N) {
        ans += B[i] + 1;
        ans -= (B[i-1] + 1) * 2;
        ans2 = max(ans, ans2);
    }

    writeln(max(ans, ans2, 0));
}