namespace AtCoder;

#nullable enable

using System.Numerics;

static class Extensions
{
    public static T[] Repeat<T>(this int time, Func<T> F) => Enumerable.Range(0, time).Select(_ => F()).ToArray();
}

class AtCoder
{
    object? Solve()
    {
        var n = Int();
        var xz = 3.Repeat(() => n.Repeat(Int));
        var min = long.MinValue / 8;
        var dp = new long[3, 3];
        for (var i = 0; i < 3; i++) for (var j = 0; j < 3; j++) dp[i, j] = min;
        dp[0, 0] = 0;
        for (var k = 0; k < n; k++)
        {
            var ep = new long[3, 3];
            for (var i = 0; i < 3; i++) for (var j = 0; j < 3; j++) ep[i, j] = min;
            for (var i = 0; i < 3; i++) for (var j = 0; j < 3; j++)
            {
                var v = dp[i, j];
                ep[i, j] = Math.Max(ep[i, j], v + xz[i][k]);
                if (i + 1 < 3 && j + 1 < 3) ep[i + 1, j + 1] = Math.Max(ep[i + 1, j + 1], v + xz[i + 1][k]);
                if (i + 2 < 3 && j + 2 < 3) ep[i + 2, j + 2] = Math.Max(ep[i + 2, j + 2], v + xz[i + 2][k]);
                if (i >= 1) ep[i - 1, j] = Math.Max(ep[i - 1, j], v + xz[i - 1][k]);
                if (i >= 2) ep[i - 2, j] = Math.Max(ep[i - 2, j], v + xz[i - 2][k]);
            }
            dp = ep;
        }
        var ans = min;
        for (var i = 0; i < 3; i++) for (var j = 0; j < 3; j++) ans = Math.Max(ans, dp[i, j]);
        return ans;
    }

    public static void Main() => new AtCoder().Run();
    public void Run()
    {
        var res = Solve();
        if (res != null)
        {
            if (res is bool yes) res = yes ? "Yes" : "No";
            sw.WriteLine(res);
        }
        sw.Flush();
    }

    string[] input = Array.Empty<string>();
    int iter = 0;
    readonly StreamWriter sw = new(Console.OpenStandardOutput()) { AutoFlush = false };

    string String()
    {
        while (iter >= input.Length) (input, iter) = (Console.ReadLine()!.Trim().Split(' '), 0);
        return input[iter++];
    }
    T Input<T>() where T : IParsable<T> => T.Parse(String(), null);
    int Int() => Input<int>();
    void Out(object? x, string? separator = null)
    {
        separator ??= Environment.NewLine;
        if (x is System.Collections.IEnumerable obj and not string)
        {
            var firstLine = true;
            foreach (var item in obj)
            {
                if (!firstLine) sw.Write(separator);
                firstLine = false;
                sw.Write(item);
            }
        }
        else sw.Write(x);
        sw.WriteLine();
    }
}