public static UInt64 HackerGrid2()
{
    bool hacker = false;
    UInt64 sl = 0;
    string[] summaryRow;
    if (hacker)
    {
        summaryRow = Console.ReadLine().Split(' ');
    }
    else
    {
        summaryRow = new string[] { "4", "4", "3" };
    }
    UInt32 row = Convert.ToUInt32(summaryRow[0]);
    UInt32 col = Convert.ToUInt32(summaryRow[1]);
    Int32 k    = Convert.ToInt32(summaryRow[2]);
    List<Tuple<UInt32, UInt32, UInt32>> tracks = new List<Tuple<UInt32, UInt32, UInt32>>(k);
    string[] rows;
    rows = new string[] { "2 2 3"
                        , "3 1 4"
                        , "4 4 4"
                        };
    for (int j = 0; j < k; j++)
    {
        if (hacker)
        {
            summaryRow = Console.ReadLine().Split(' ');
        }
        else
        {
            summaryRow = rows[j].Split(' ');
        }
        UInt32 trow  = Convert.ToUInt32(summaryRow[0]);
        UInt32 start = Convert.ToUInt32(summaryRow[1]);
        UInt32 end   = Convert.ToUInt32(summaryRow[2]);
        tracks.Add(new Tuple<UInt32, UInt32, UInt32>(trow, start, end));
    }
    tracks.Sort();
    UInt32 lastRow = 0;
    UInt32 lastEnd = 0;
    sl = (UInt64)row * (UInt64)col;
    foreach (Tuple<UInt32, UInt32, UInt32> ts in tracks)
    {
        UInt32 trow  = ts.Item1;
        UInt32 start = ts.Item2;
        UInt32 end   = ts.Item3;

        if (trow > lastRow || start > lastEnd)
        {
            sl -= end - start + 1;
            lastEnd = end;
        }
        else if (end > lastEnd)
        {
            sl -= end - lastEnd;
            lastEnd = end;
        }
        lastRow = trow;
    }
    Console.WriteLine(sl);
    return sl;
}