H, W, x, y, N = map(int, input().split())

dp = [0, -1 << 60]

for nx, ny, c in [map(int, input().split()) for _ in range(N)]:
    ndp = [dp[1] + c, max(dp)]
    if x == nx or y == ny:
        ndp[0] = max(ndp[0], dp[0] + c)
    x = nx
    y = ny
    dp = ndp

print(max(dp))