#include <bits/stdc++.h>
using namespace std;

using ll = long long;

int main()
{
	int h, w, K;
	cin >> h >> w >> K;
	vector<vector<ll>> p(h, vector<ll>(w));
	ll x, y, v;
	for(int i = 0; i < K; i++)
	{
		cin >> x >> y >> v;
		x--; y--;
		p[x][y] = v;
	}
	const ll mod = 998244353;
	
	ll ans = 0;
	for(int i = 0; i < h; i++)
	{
		for(int j = 0; j < w; j++)
		{
			for(int k = 0; k < h; k++)
			{
				for(int l = 0; l < w; l++)
				{
					if(k + l >= i + j && k - l >= i - j)
					{
						ans += p[k][l];
						ans %= mod;
					}
				}
			}
		}
	}
	cout << ans << endl;
	return 0;
}