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, core.stdc.string; void main() { auto N = readln.chomp.to!int; auto A = readln.split.map!(to!long).array; A.sort(); auto dp = new long[][](N+1, 3); // down, stay, up foreach (i; 0..N+1) foreach (j; 0..3) dp[i][j] = 1L << 59; dp[0][0] = 0; foreach (i; 0..N) { if (i != 0) { dp[i+1][0] = min(dp[i+1][0], dp[i][1] + A[i] - A[i-1]); } dp[i+1][1] = min(dp[i+1][1], dp[i][2]); if (i != N - 1) { dp[i+1][2] = min(dp[i+1][2], min(dp[i][0], dp[i][1]) + A[i+1] - A[i]); } } dp[N].reduce!min.writeln; }