H,W,sx,sy,N=map(int,input().split())
inf = 10**30
dp = [-inf]*(N+1)
dp[0] = 0
d = [(sx,sy)]
for i in range(N):
    x,y,c=map(int,input().split())
    if i>=1:
        dp[i+1] = max(dp[i+1], dp[i-1] + c)
    if d[-1][0] == x or d[-1][1] == y or (d[-1][0]+d[-1][1]==x+y) or (d[-1][0]-d[-1][1]==x-y):
        dp[i+1] = max(dp[i+1], dp[i] + c)
    d.append((x,y))
print(max(dp))