from itertools import product

INF = 10**18


def can_reach(src, dst):
    src_x, src_y = src
    dst_x, dst_y = dst

    for cx, cy in product((-1, 0, 1), repeat=2):
        if cx == cy == 0:
            continue
        if cx * src_x + cy * src_y == cx * dst_x + cy * dst_y:
            return True

    return False


H, W, sx, sy, N = [int(s) for s in input().split()]
curr_x, curr_y = sx, sy

dp = [-INF, 0]
for _ in range(N):
    x, y, c = [int(s) for s in input().split()]
    ndp = [-INF, -INF]

    if can_reach((curr_x, curr_y), (x, y)):
        ndp[0] = max(dp[0], dp[1])
        ndp[1] = max(dp[0], dp[1]) + c
    else:
        ndp[0] = max(dp[0], dp[1])
        ndp[1] = dp[0] + c

    curr_x, curr_y = x, y
    dp = ndp

print(max(dp))