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