#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;
const int N = 3e5 + 1;
ll dp[N][4];
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 w1, h1, n;
    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];
    }
    const ll inf = 1e18;
    vector<vector<ll>> pref_mx(w1 + 1, vector<ll>(h1 + 1, -inf));
    for (ll l = 1; l <= w1; l++) {
        for (ll r = 1; r <= h1; r++) {
            for (ll i = 0; i < n; i++) {
                if (h[i] <= r && l % w[i] == 0) {
                    dp[l][r] = max(dp[l][r], dp[l][r - h[i]] + l/w[i]);
                }
                if (w[i] <= l && r % h[i] == 0) {
                    dp[l][r] = max(dp[l][r], dp[l - w[i]][r] + r/h[i]);
                }
            }
            ll k1 = -inf, k2 = -inf;
            if (l > 0) {
                k1 = pref_mx[l - 1][r];
            }
            if(r>0) {
                k2 = pref_mx[l][r - 1];
            }
            pref_mx[l][r] = max(max(k1, k2), dp[l][r]);
            dp[l][r] = max(dp[l][r], pref_mx[l][r]);
            //cout << l << ' ' << r << ' ' << dp[l][r] << '\n';
        }
    }
    cout << dp[w1][h1] <<'\n';

}