#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(){
    int n, m, q; cin >> n >> m >> q;
    vector<vector<bool>> pa(n+10, vector<bool>(m+10, false));
    for(int i = 0; i < q; i++){
        int a, b; cin >> a >> b;
        pa[a][b] = true;
    }

    vector<vector<int>> dp(n+10, vector<int>(m+10, 0));
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++){
            dp[i][j] = dp[i-1][j-1];
            if(pa[i][j]) dp[i][j]++;
            dp[i][j] = max(dp[i][j], dp[i][j-1]);
            dp[i][j] = max(dp[i][j], dp[i-1][j]);
            // cerr << dp[i][j] << " ";
        }
        // cerr << endl;
    }
    int ans = 0;
    for(int i = 0; i <= n; i++){
        for(int j = 0; j <= m; j++){
            ans = max(ans, dp[i][j]);
        }
    }
    cout << ans << endl;
    return 0;
}