h,w,k = map(int,input().split())
xyv = {}
for _ in range(k):
    x,y,v = map(int,input().split())
    xyv[(x-1,y-1)] = v
c = [[0]*w for _ in range(h)]
for i in range(h):
    for j in range(w):
        for x in range(h):
            for y in range(w):
                if x+y>=i+j and x-y>=i-j:
                    c[x][y] += 1
ans = 0
for x in range(h):
    for y in range(w):
        if (x,y) in xyv:
            ans += xyv[(x,y)]*c[x][y]
print(ans%998244353)