#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
#define FOR(i,l,r) for(ll i=l;i<r;i++)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,l,r) for(ll i=r-1;i>=l;i--)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define P pair<ll,ll>
#define F first
#define S second
#define BS(A,x) binary_search(ALL(A),x)
#define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin())
#define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin())
#define COU(A,x) UB(A,x)-LB(A,x)
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
using mint=modint1000000007;
//using mint=modint998244353;
bool comp(P&a,P&b){if(a.F!=b.F)return a.F<b.F;return a.S>b.S;}
ll op(ll a,ll b){return max(a,b);}
ll e(){return 0;}
signed main(){
  ll N,M,Q;cin>>N>>M>>Q;
  vector<P>A(Q);REP(i,Q)cin>>A[i].F>>A[i].S;
  sort(ALL(A),comp);
  segtree<ll,op,e>S(M+1);
  REP(i,Q){
    S.set(A[i].S,max(S.prod(0,A[i].S)+1,S.get(A[i].S)));
  }
  cout<<S.all_prod()<<endl;
  return 0;
}