#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
using ll=long long;
using ld=double;
ld pie=3.14159265359;
ll mod=998244353;
ll inf=100000;
int main(){
    ll h,w,k;
    cin >> h >> w >> k;
    vector<ll>x(k),y(k),v(k);
    vector<vector<ll>>g(h,vector<ll>(w,0));
    for (ll i = 0; i < k; i++)
    {
        cin >> x[i] >> y[i] >> v[i];
        x[i]--,y[i]--;
        g[x[i]][y[i]]=v[i];
    }
    ll ans=0;
    for (ll i = 0; i < h; i++)
    {
        for (ll j = 0; j < w; j++)
        {
            for (ll kk = 0; kk < h; kk++)
            {
                for (ll l = 0; l < w; l++)
                {
                    if (i+j<=kk+l&&i-j<=kk-l)
                    {
                        ans+=g[kk][l];
                        ans%=mod;
                    }
                    
                }
                
            }
            
        }
    }
    cout << ans <<endl;
}