#include<stdio.h>
long long int can(long long int x1, long long int y1, long long int x2, long long int y2)
{
	if (x1 == x2 || y1 == y2 || x1 + y1 == x2 + y2 || x1 - y1 == x2 - y2)
		return 1;
	else
		return -1;
}
long long int x[500005], y[500005], c[500005];
long long int dp[500005];
int main()
{
	long long int h, w, n;
	scanf("%lld %lld", &h, &w);
	scanf("%lld %lld", &x[0], &y[0]);
	scanf("%lld", &n);
	long long int i;
	for (i = 1; i <= n; i++)
		scanf("%lld %lld %lld", &x[i], &y[i], &c[i]);
	dp[0] = 0;
	if (can(x[0], y[0], x[1], y[1]) > 0)
		dp[1] = c[1];
	else
		dp[1] = 0;
	for (i = 2; i <= n; i++)
	{
		dp[i] = dp[i - 2] + c[i];
		if (can(x[i], y[i], x[i - 1], y[i - 1]) > 0)
		{
			if (dp[i] < dp[i - 1] + c[i])
				dp[i] = dp[i - 1] + c[i];
		}
		if (dp[i - 1] < dp[i - 2])
			dp[i - 1] = dp[i - 2];
	}
	if (dp[n - 1] > dp[n])
		dp[n] = dp[n - 1];
	printf("%lld\n", dp[n]);
	return 0;
}