#include <iostream>
#include <vector>
#include <iomanip>
#include <algorithm>
#include <map>
#include <cmath>
#include <bitset>
#include <string>
#include <queue>
#include <stack>
#include <set>
#include <tuple>
#include <atcoder/all>
#include <sstream> 
#include <regex>
#include <fstream> // ifstream ifs("workspacetop.txt");
using namespace atcoder;
using mint = modint998244353;
//using mint = modint1000000007;
using namespace std;
using ll = long long;
static const double pi = 3.141592653589793;
const int INF = (1<<29);
const ll mod = 998244353;

int main(){

    int h,w,k;
    cin >> h >> w >> k;
    vector table(h,vector<int>(w,0));

    for(int i=0;i<k;i++){
        int x,y,v;cin >> x >> y >> v;
        x--;y--;
        table[x][y] = v;
    }

    mint ans = 0;

    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            for(int x=0;x<h;x++){
                for(int y=0;y<w;y++){
                    if(x+y>=i+j && x-y>=i-j){
                        ans += table[x][y];
                    }
                }
            }
        }
    }
    cout << ans.val() << endl;
}