def main():
    h, w, sy, sx, n = list(map(int, input().split()))
    py, px = sy-1, sx-1
    inf = 1<<60
    dp = [-inf, 0]
    for _ in range(n):
        y, x, c = list(map(int, input().split()))
        y, x = y-1, x-1
        if py == y or px == x or py-px == y-x or py+px == y+x:
            dp = [dp[1], max(dp)+c]
        else:
            dp = [dp[1], dp[0]+c]
        py, px = y, x
    return max(dp)

print(main())