#include <bits/stdc++.h>
#include <atcoder/all>
#define OVERLOAD_REP(_1, _2, _3, name, ...) name
#define REP1(i,n) for (auto i = std::decay_t<decltype(n)>{}; (i) != (n); ++(i))
#define REP2(i,l,r) for (auto i = (l); (i) != (r); ++(i))
#define rep(...) OVERLOAD_REP(__VA_ARGS__, REP2, REP1)(__VA_ARGS__)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
using namespace std;
using namespace atcoder;
using ll = long long;
using ull = unsigned long long;
using P = pair<int,int>;
using LP = pair<long long,long long>;
using SP = pair<string,string>;
using vi = vector<int>;
using vl = vector<long long>;
using vs = vector<string>;
using vc = vector<char>;
using mint1 = modint1000000007;
using mint9 = modint998244353;
const int INF = 2e9;
const long long LINF = 4e18;
const int di[] = {0,1,0,-1,-1,1,-1,1};
const int dj[] = {1,0,-1,0,1,1,-1,-1};
template<class T> inline bool chmin(T& a, T b){if(a>b){a=b;return true;}return false;}
template<class T> inline bool chmax(T& a, T b){if(a<b){a=b;return true;}return false;}
void YesNo (bool ok , const string &s , const string &t) {if(ok) cout << s << endl; else cout << t << endl;} 


//-----def end-----//


int main () {
    int h , w , k;
    cin >> h >> w >> k;
    vector<int> x(k) , y(k) , v(k);
    rep(i , k) cin >> x[i] >> y[i] >> v[i];
    rep(i , k) x[i]-- , y[i]--;
    map<pair<int,int> , int> mp;
    rep(i , k) mp[{x[i],y[i]}] = v[i];
    mint9 res = 0;
    rep(i , h) rep(j , w) {
        int cnt = 0;
        rep(di , h-i) {
            rep(dj , -cnt , cnt+1) {
                int ni = i+di , nj = j+dj;
                res += mp[{ni,nj}];
            }
            cnt++;
        }
    }
    cout << res.val() << endl;
	return 0;
}