#include <bits/stdc++.h>
using namespace std;
#include <atcoder/dsu>
using namespace atcoder;

const int INF = 1e9;

int main() {
    int H, W, N; cin >> H >> W >> N;
    dsu d(H+W);
    for (int i = 0; i < N; i++) {
        int a, b; cin >> a >> b;
        a--; b--;
        d.merge(a, b+H);
    }
    vector<vector<int>> G = d.groups();
    int K = (int)G.size();
    vector<int> dpmin(H+1, INF), dpmax(H+1, -INF);
    dpmin[0] = dpmax[0] = 0;
    for (int i = 0; i < K; i++) {
        int rc = 0, cc = 0;
        for (int v : G[i]) {
            if (v < H) rc++;
            else cc++;
        }
        for (int j = H; j >= 0; j--) {
            if (dpmin[j] != INF) {
                dpmin[j+rc] = min(dpmin[j+rc], dpmin[j] + cc);
                dpmax[j+rc] = max(dpmax[j+rc], dpmax[j] + cc);
            }
        }
    }
    int ans = 0;
    for (int i = 0; i <= H; i++) {
        if (dpmin[i] != INF) {
            ans = max(ans, i*(W-dpmin[i])+(H-i)*dpmin[i]);
            ans = max(ans, i*(W-dpmax[i])+(H-i)*dpmax[i]);
        }
    }
    cout << ans << endl;
}