#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <fstream>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>
#include <numeric>
#include <iterator>

typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;

ll gcd(ll a, ll b) {
    if (a < b)swap(a, b);
    if (b == 0)return a;
    return gcd(b, a % b);
}
int lcm(int a, int b) {
    return a * b / gcd(a, b);
}




int main()
{

    int Q;
    Q = 1;
    //cin >> Q;



    while (Q--) {
        int n;
        cin >> n;
        int m;
        cin >> m;
        int k;
        cin >> k;
        vector<vector<ll>>p(n + 3, vector<ll>(m + 3));
        for (int i = 0; i < k; i++) {
            int x, y;
            cin >> x >> y;
            int t;
            cin >> t;
            p[x][y] = t;
          
        }
        ll d = 998244353;
        
        ll ans = 0;
        
        
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= m; j++) {
                for (int t = i; t <= n; t++) {
                    int r = t - i;
                    int a = max(j - r, 1);
                    int b = min(j + r, m);
                    for (int h = a; h <= b; h++) {
                        ans += p[t][h];
                        ans %= d;
                   }
                }
                //cout << ans << endl;
            }
        }
        cout << ans;

    }
        return 0;
}