#include <iostream>
#include <cmath>
#include <vector>
#include <cstdio>
#include <cstdlib>
#include <set>
#include <string>
#include <algorithm>
#include <stack>
#include <map>
#include <fstream>

#pragma GCC optimize("no-stack-protector")
#pragma comment(linker, "/STACK:99999999999999999")

using namespace std;

const long double eps = 1e-10;
const long double inf = 999999999999999;
const long double pi = 3.141592653589793238462643383279;

ostream& operator << (ostream& out, const vector<int>& s){
    for (int i = 0; i < s.size(); ++i){
        out << s[i] << ' ';
    }
    return out;
}

ostream& operator << (ostream& out, pair<int, int>& a){
    out << a.first << ' ' << a.second;
    return out;
}

int main(){
//    freopen("coins.in", "r", stdin);
//    freopen("coins.out", "w", stdout);
//    cout.precision(10);
//    cout << fixed;
//    ifstream fin("input.txt");
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int n, m, k;
    cin >> n >> m >> k;
    map<int, int> cities;
    map<int, int> teams;
    for (int i = 0; i < k; ++i){
        int a, b;
        cin >> a >> b;
        ++cities[a];
        ++teams[b];
    }
    int ans = 0;
    for (auto now: cities){
        ans = max(ans, (int)ceil((double)now.second / 3));
    }
    for (auto now: teams){
        ans = max(ans, (int)ceil((double)now.second / 3));
    }
    cout << ans;

}