# https://yukicoder.me/problems/no/3597

def same_line(h0, w0, h1, w1):
    if h0 == h1 or w0 == w1:
        return True
    elif h0 - w0 == h1 - w1:
        return True
    elif h0 + w0 == h1 + w1:
        return True
    return False



def main():
    H, W, sx, sy, N = map(int, input().split())
    xyc = []
    for _ in range(N):
        x, y, c = map(int, input().split())
        xyc.append((x, y, c))

    dp = [-1] * 2
    dp[0] = 0
    prev_x = sx
    prev_y = sy
    for x, y, c in xyc:
        new_dp = [-1] * 2

        new_dp[0] = max(new_dp[0], dp[0])
        new_dp[0] = max(new_dp[0], dp[1])
        new_dp[1] = max(new_dp[1], dp[0] + c)
        if same_line(prev_x, prev_y, x, y):
            new_dp[1] = max(new_dp[1], dp[1] + c)
        dp = new_dp
        prev_x = x
        prev_y = y

    print(max(dp))





if __name__ == "__main__":
    main()