#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N=1e6+7;
int bj_x[N],bj_y[N];
const int p=998244353;
int qpow(int n,int k){
	n%=p;
	int ans=1;
    while(k){
        if(k&1){
            ans=ans*n%p;
        }
        n=n*n%p;
        k>>=1;
    }
    return ans;
}
int n,m,k;
signed main(){
	freopen("plusminus.in","r",stdin);
	freopen("plusminus.out","w",stdout);
	cin>>n>>m>>k;
	for(int i=1;i<=k;i++){
		int x,y,val;
		cin>>x>>y>>val;
		bj_x[x]=1;
		bj_y[y]=1;
	}
	if(m%2!=n%2){
		cout<<0;
	}
	else{
		cout<<qpow(2,(n*m-n-m-k+1))<<"\n";
	}

	return 0;
}