H,W,sx,sy,N = list(map(int,input().split()))
sx -= 1;sy -= 1
point = [(sx,sy,0)]
for _ in range(N):
    x,y,c = list(map(int,input().split()))
    x -= 1;y -= 1
    point.append((x,y,c))

def can(i,j):
    x,y,_ = point[i]
    xx,yy,_ = point[j]
    return x == xx or y == yy

INF = 10**18
dp = [[-INF, -INF] for _ in range(N+1)]
dp[0][0] = 0
dp[0][1] = 0
for i in range(N):
    if(can(i,i+1)):dp[i+1][0] = dp[i][0] + point[i+1][2]
    dp[i+1][0] = max(dp[i+1][0], dp[i][1] + point[i+1][2])
    dp[i+1][1] = max(dp[i][0], dp[i][1])

print(max(dp[-1]))