H,W,K=map(int,input().split())
XYV=[list(map(int,input().split())) for _ in range(K)]
Map = [[0]*W for _ in range(H)]
for x,y,v in XYV:
    Map[x-1][y-1]=v
MOD=998244353
ans=0
for i in range(H):
    for j in range(W):
        for x in range(H):
            for y in range(W):
                if i+j<=x+y and i-j<=x-y:
                    ans+=Map[x][y]
                    ans%=MOD
print(ans)