h, w, sx, sy, n = map(int, input().split())
dp = [0, 0]
for _ in range(n):
    x, y, c = map(int, input().split())
    dp = [dp[1], max(dp[0] + c, dp[1] + (c if sx == x or sy == y or x+y == sx+sy or x-y == sx-sy else 0))]
    sx, sy = x, y
print(max(dp))