#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
#endif
using ll = long long;
using ld = long double;
const ll INF = 1ll<<60;
const ld EPS = 1.0/1e9;
#define endl "\n"
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
#define del(x) sort(all(x)); x.erase(unique(all(x)),x.end());

int main(){
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  ll n,m,q; cin >> n >> m >> q;
  vector<pair<ll,ll>>x;
  rep(i,0,q){
    ll a,b; cin >> a >> b;
    x.emplace_back(a,-b);
  }
  sort(all(x));
  vector<ll>dp(q+1,INF);
  fore(c,x){
    ll a,b; tie(a,b)=c;
    ll f=lower_bound(all(dp),-b)-dp.begin();
    dp[f]=-b;
  }
  cout << lower_bound(all(dp),INF)-dp.begin() << endl;
}