import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		int h = Integer.parseInt(sa[0]);
		int w = Integer.parseInt(sa[1]);
		int sx = Integer.parseInt(sa[2]) - 1;
		int sy = Integer.parseInt(sa[3]) - 1;
		int n = Integer.parseInt(sa[4]);
		int[] x = new int[n];
		int[] y = new int[n];
		int[] c = new int[n];
		for (int i = 0; i < n; i++) {
			sa = br.readLine().split(" ");
			x[i] = Integer.parseInt(sa[0]) - 1;
			y[i] = Integer.parseInt(sa[1]) - 1;
			c[i] = Integer.parseInt(sa[2]);
		}
		br.close();

		long[] dpx = new long[h];
		long[] dpy = new long[w];
		long[] dpz = new long[h + w];
		long[] dpn = new long[h + w];
		long[] ans = new long[n];
		{
			int xi = x[0];
			int yi = y[0];
			int zi = xi + yi;
			int ni = xi - yi + w;
			long v2 = c[0];
			if (xi == sx ||
					yi == sy ||
					zi == sx + sy ||
					ni == sx - sy + w) {
				dpx[xi] = v2;
				dpy[yi] = v2;
				dpz[zi] = v2;
				dpn[ni] = v2;
				ans[0] = v2;
			}
		}
		for (int i = 1; i < n; i++) {
			ans[i] = ans[i - 1];
			int xi = x[i];
			int yi = y[i];
			int zi = xi + yi;
			int ni = xi - yi + w;
			long v1 = 0;
			v1 = Math.max(v1, dpx[xi]);
			v1 = Math.max(v1, dpy[yi]);
			v1 = Math.max(v1, dpz[zi]);
			v1 = Math.max(v1, dpn[ni]);
			if (i >= 2) {
				v1 = Math.max(v1, ans[i - 2]);
			}
			long v2 = v1 + c[i];
			dpx[xi] = Math.max(dpx[xi], v2);
			dpy[yi] = Math.max(dpy[yi], v2);
			dpz[zi] = Math.max(dpz[zi], v2);
			dpn[ni] = Math.max(dpn[ni], v2);
			ans[i] = Math.max(ans[i], dpx[xi]);
			ans[i] = Math.max(ans[i], dpy[yi]);
			ans[i] = Math.max(ans[i], dpz[zi]);
			ans[i] = Math.max(ans[i], dpn[ni]);
		}
		System.out.println(ans[n - 1]);
	}
}