#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
using mint = modint998244353;
const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A& a, const B& b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A& a, const B& b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int h, w, k; cin >> h >> w >> k;
	vector<vector<int>>a(h, vector<int>(w));
	rep(i, k) {
		int x, y, v; cin >> x >> y >> v;
		x--, y--;
		a[x][y] = v;
	}
	mint ans = 0;
	rep(i, h)rep(j, w) {
		rep(k, h)rep(l, w) {
			if (k + l < i + j)continue;
			if (k - l < i - j)continue;
			ans += a[k][l];
		}
	}
	cout << ans.val() << endl;
	return 0;
}