#define _CRT_SECURE_NO_WARNINGS
#define debug(l) cerr<<" smotri huinyi : "<<#l<<' '<<l<<'\n';
#include "bits/stdc++.h"
using namespace std;
#define all(a) a.begin(), a.end()
typedef long long ll;
typedef long double ld;
signed main() {
#ifdef _DEBUG
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    srand(time(NULL));
    ll n, w1, h1;
    cin >> w1 >> h1 >> n;
    vector<ll> w(n), h(n);
    vector<vector<ll>> dp(w1 + 1, vector<ll>(h1 + 1,0));
    for (ll i = 0; i < n; i++) {
        cin >> w[i] >> h[i];
        dp[w[i]][h[i]] = 1;
    }
    for (ll i = 1; i <= w1; i++) {
        for (ll j = 1; j <= h1; j++) {
            for (ll k = 1; k <= i; k++) {
                dp[i][j] = max(dp[k][j] + dp[i-k][j], dp[i][j]);
            }
            for (ll k = 1; k <= j; k++) {
                dp[i][j] = max(dp[i][k] + dp[i][j - k], dp[i][j]);
            }
        }
    }
    cout << dp[w1][h1] << '\n';


}