#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

const ll modc = 998244353;

int main(){

    ll H, W, K, ans=0, x, y, w;
    cin >> H >> W >> K;
    vector<vector<ll>> c(H+1, vector<ll>(W+1));
    for (int i=0; i<K; i++){
        cin >> x >> y >> w;
        c[x][y] = w;
    }

    for (int i=1; i<=H; i++){
        for (int j=1; j<=W; j++){
            for (int x=1; x<=H; x++){
                for (int y=1; y<=W; y++){
                    if (x+y>=i+j && x-y>=i-j){
                        ans += c[x][y];
                        ans %= modc;
                    }
                }
            }
        }
    }

    cout << ans << endl;

    return 0;
}