#nullable enable

#region
var (_input, _iter) = (Array.Empty<string>(), 0);
T I<T>() where T : IParsable<T>
{
    while (_iter >= _input.Length) (_input, _iter) = (Console.ReadLine()!.Trim().Split(' '), 0);
    return T.Parse(_input[_iter++], null);
}
#endregion

static T[] Range<T>(int n, Func<T> F) => Enumerable.Range(0, n).Select(_ => F()).ToArray();

var h = I<int>();
var w = I<int>();
var sx = I<int>();
var sy = I<int>();
var n = I<int>();
var qz = Range(n, () => (I<int>(), I<int>(), I<int>()));

bool R(int x1, int y1, int x2, int y2)
{
    if (x1 == x2 || y1 == y2) return true;
    if (x1 - y1 == x2 - y2) return true;
    if (x1 + y1 == x2 + y2) return true;
    return false;
}
var s1 = 0L;
var s2 = 0L;
var (x1, y1) = (sx, sy);
var (x2, y2) = (sx, sy);
foreach (var (x, y, c) in qz)
{
    if (R(x2, y2, x, y))
    {
        (s1, s2) = (Math.Max(s1, s2), Math.Max(s1 + c, s2 + c));
    }
    else
    {
        (s1, s2) = (Math.Max(s1, s2), Math.Max(s1 + c, s2));        
    }
    (x1, y1) = (x2, y2);
    (x2, y2) = (x, y);
}
var ans = Math.Max(s1, s2);
Console.WriteLine(ans);