#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
namespace my{
using ml=atcoder::modint998244353;
auto&operator>>(istream&i,ml&x){int t;i>>t;x=t;return i;}
auto&operator<<(ostream&o,const ml&x){return o<<(int)x.val();}
#define LL(...) ll __VA_ARGS__;lin(__VA_ARGS__)
#define FO(n) for(ll ij=n;ij-->0;)
#define FOR(i,...) for(auto[i,i##stop,i##step]=range(0,__VA_ARGS__);i<i##stop;i+=i##step)
#define fo(i,...) FO##__VA_OPT__(R)(i __VA_OPT__(,__VA_ARGS__))
#define fe(a,e,...) for(auto&&__VA_OPT__([)e __VA_OPT__(,__VA_ARGS__]):a)
#define schrodinger(p,c) (p?c:remove_cvref_t<decltype(c)>{})
#define base_operator(op,type) auto operator op(const type&v)const{auto copy=*this;return copy op##=v;}
#define single_testcase void solve();}int main(){my::io();my::solve();}namespace my{
void io(){cerr<<endl;cin.tie(nullptr)->sync_with_stdio(0);cout<<fixed<<setprecision(15);}
using ll=long long;
constexpr auto range(ll s,ll b){ll a=0;if(s)swap(a,b);return array{a-s,b,1-s*2};}
constexpr auto range(ll s,ll a,ll b,ll c=1){return array{a-s,b,(1-s*2)*c};}
const string newline{char(10)};
const string space{char(32)};

template<class...A>using pack_back_t=tuple_element_t<sizeof...(A)-1,tuple<A...>>;

template<class V>concept vectorial=is_base_of_v<vector<typename remove_cvref_t<V>::value_type>,remove_cvref_t<V>>;
template<class V>constexpr int rank(){if constexpr(vectorial<V>)return rank<typename V::value_type>()+1;else return 0;}
template<class T>struct core_t_helper{using core_t=T;};
template<vectorial V>struct core_t_helper<V>{using core_t=typename core_t_helper<typename V::value_type>::core_t;};
template<class T>using core_t=core_t_helper<T>::core_t;
template<class V>istream&operator>>(istream&i,vector<V>&v){fe(v,e)i>>e;return i;}
template<class V>ostream&operator<<(ostream&o,const vector<V>&v){ll n=v.size();fo(i,n)o<<v[i]<<schrodinger(i<n-1,vectorial<V>?newline:space);return o;}

template<class V>struct vec;
template<int rank,class T>struct hvec_helper{using type=vec<typename hvec_helper<rank-1,T>::type>;};
template<class T>struct hvec_helper<0,T>{using type=T;};
template<int rank,class T>using hvec=typename hvec_helper<rank,T>::type;

template<class V>struct vec:vector<V>{
  static constexpr int R=rank<vec<V>>();
  using C=core_t<V>;
  using vector<V>::vector;
  vec(const vector<V>&v){vector<V>::operator=(v);}
  vec(const auto&...a)requires(sizeof...(a)>=3){resizes(a...);}
  void resizes(const auto&...a){*this=make(a...);}
  static auto make(ll n,const auto&...a){if constexpr(sizeof...(a)==1)return vec<C>(n,array{a...}[0]);else return vec<decltype(make(a...))>(n,make(a...));}

  vec&operator^=(const vec&u){this->insert(this->end(),u.begin(),u.end());return*this;}
  vec&operator+=(const vec&u){vec&v=*this;assert(v.size()==u.size());fo(i,v.size())v[i]+=u[i];return v;}
  vec&operator-=(const vec&u){vec&v=*this;assert(v.size()==u.size());fo(i,v.size())v[i]-=u[i];return v;}
  base_operator(^,vec)
  base_operator(+,vec)
  base_operator(-,vec)

  vec&operator++(){fe(*this,e)++e;return*this;}
  vec&operator--(){fe(*this,e)--e;return*this;}

  ll size()const{return vector<V>::size();}
};
template<class...A>requires(sizeof...(A)>=2)vec(const A&...a)->vec<hvec<sizeof...(A)-2,pack_back_t<A...>>>;
vec(ll)->vec<ll>;

void lin(auto&...a){(cin>>...>>a);}
void pp(const auto&...a){ll n=sizeof...(a);((cout<<a<<schrodinger(--n>0,space)),...);cout<<newline;}

single_testcase
void solve(){
  LL(H,W,K);
  vec v(H,W,0);
  fo(K){
    LL(a,b,c);a--,b--;
    v[a][b]=c;
  }

  auto f=[&](ll i,ll j){
    ml r=0;
    fo(x,H)fo(y,W)if(x+y>=i+j&&x-y>=i-j)r+=v[x][y];
    return r;
  };

  ml ans=0;
  fo(i,H)fo(j,W)ans+=f(i,j);
  pp(ans);
}}