/* -*- coding: utf-8 -*-
 *
 * 3597.cc:  No.3597 Queen Score Attack 2 - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 500000;
const long long LINF = 1LL << 60;

/* typedef */

using ll = long long;

/* global variables */

ll dp[MAX_N + 1];

/* subroutines */

bool move(int x0, int y0, int x1, int y1) {
  return x0 == x1 || y0 == y1 || abs(x1 - x0) == abs(y1 - y0);
}

void setmax(ll &a, ll b) { if (a < b) a = b; }

/* main */

int main() {
  int h, w, sx, sy, n;
  scanf("%d%d%d%d%d", &h, &w, &sx, &sy, &n);

  ll maxdp = -LINF;
  int px = sx, py = sy;
  for (int i = 0; i < n; i++) {
    int xi, yi, ci;
    scanf("%d%d%d", &xi, &yi, &ci);

    dp[i + 1] = maxdp + ci;
    if (move(px, py, xi, yi))
      setmax(dp[i + 1], dp[i] + ci);
    setmax(maxdp, dp[i]);
    px = xi, py = yi;
  }

  ll maxsc = *max_element(dp, dp + n + 1);
  printf("%lld\n", maxsc);

  return 0;
}