#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
//const bool debug = false;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
bool comp(const P& lh, const P& rh) {
	if (lh.first < rh.first)return true;
	else if (lh.first > rh.first)return false;
	return lh.second > rh.second;
}
template<class T> int LIS(vector<T> a, bool is_strong = true) {
	const T INF = 1 << 30; // to be set appropriately
	int n = (int)a.size();
	vector<T> dp(n, INF);
	for (int i = 0; i < n; ++i) {
		if (is_strong) *lower_bound(dp.begin(), dp.end(), a[i]) = a[i];
		else *upper_bound(dp.begin(), dp.end(), a[i]) = a[i];
	}
	return lower_bound(dp.begin(), dp.end(), INF) - dp.begin();
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, m, q; cin >> n >> m >> q;
	vector<P>v(q);
	rep(i, q) {
		int a, b; cin >> a >> b; a--; b--;
		v[i] = { a,b };
	}
	sort(all(v), comp);
	vector<int>v2(q);
	rep(i, q)v2[i] = v[i].second;
	cout << LIS(v2) << endl;
	return 0;
}