#include <bits/stdc++.h>
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
const ll ILL=2167167167167167167;
const int INF=2100000000;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,T b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
bool yneos(bool a,bool upp=0){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;}
template<class T> void vec_out(vector<T> &p,int ty=0){
    if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
    else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;}
template<class T> bool inside(T l,T x,T r){return l<=x&&x<r;}


#include <atcoder/dsu>

void solve();
// CYAN / FREDERIC
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    rep(i, 0, t) solve();
}

void solve(){
    int H, W, N;
    cin >> H >> W >> N;
    atcoder::dsu T(H + W);
    rep(i, 0, N){
        int a, b;
        cin >> a >> b;
        a--, b--;
        T.merge(a, b + H);
    }
    auto table = T.groups();
    vector<pair<int, int>> dp(H + 1, {-INF, -INF});
    dp[0] = {0, 0};
    for (auto x : table) if (!x.empty()){
        int a = 0, b = 0;
        for (auto y : x){
            if (y < H) a++;
            else b++;
        }
        auto n_dp = dp;
        rep(i, 0, H + 1) if (dp[i].second != -INF){
            auto tmp = dp[i];
            tmp.first -= b;
            tmp.second += b;
            chmax(n_dp[i + a], tmp);
        }
        swap(n_dp, dp);
    }
    int ans = 0;
    rep(i, 0, H + 1) if (dp[i].second != -INF){
        chmax(ans, i * (W - dp[i].second) + (H - i) * dp[i].second);
        chmax(ans, i * (W + dp[i].first)  + (i - H) * dp[i].first);
    }
    cout << ans << "\n";
}