H,W,y0,x0,N = map(int,input().split())
A = [(y0,x0,0)]+[list(map(int,input().split())) for _ in range(N)]
def dist(i,j):
    y0,x0,_ = A[i]
    y1,x1,_ = A[j]
    d = 2
    if y0==y1 and x0==x1:
        d = 0
    elif y0==y1 or x0==x1 or y1-y0==x1-x0 or y1-y0==x0-x1:
        d = 1
    return d
dp = [0 for _ in range(N+1)]
dp[N] = A[N][2]
y1,x1,c1 = A[N]
y0,x0,c0 = A[N-1]
d = dist(N-1,N)
if d<=1:
    dp[N-1] = c0+c1
else:
    dp[N-1] = max(c0,c1)
dpmax = dp[N]
for i in range(N-2,0,-1):
    y0,x0,c0 = A[i]
    y1,x1,c1 = A[i+1]
    d01 = dist(i,i+1)
    dp[i] = c0+dpmax
    if d01<=1:
        dp[i] = max(dp[i],c0+dp[i+1])
    else:
        dp[i] = max(dp[i],dp[i+1])
    dpmax = max(dp[i+1],dpmax)
d01 = dist(0,1)
dpmax = max(dp[2:])
if d01<=1:
    print(max(dp[1],dpmax))
else:
    print(dpmax)