#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    ll h, w, k; cin >> h >> w >> k;
    vector<vector<ll>> cost(h, vector<ll>(w, 0));
    rep(i, k){
        ll x, y, v; cin >> x >> y >> v; x--; y--;
        cost[x][y]=v;
    }

    ll ans = 0;
    for(ll i=0; i<h; i++) for(ll j=0; j<w; j++){
        for(ll x=0; x<h; x++) for(ll y=0; y<w; y++){
            if((x+y)>=(i+j) && (x-y)>=(i-j)){
                ans = (ans + cost[x][y])%MOD2;
            }
        }
    }

    cout << ans << endl;
}