#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll MOD = 1000000007;
using P = pair<int,int>;
#define rep(i, n) for(int i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()

int main(){
    int n,m,q;
    cin >> n >> m >> q;
    vector<int> cx(q,MOD),cy(q,MOD);
    rep(i,q){
        int a,b;
        cin >> a >> b;
        int low = lower_bound(all(cx),a) - cx.begin();
        int up = upper_bound(all(cx),a) - cx.begin();
        if(low == up){
            if(low && cy[low-1] >= b) continue;
            cx[low] = a; cy[low] = b;
        }else{
            int itr = lower_bound(cy.begin()+low, cy.begin()+up, b) - cy.begin();
            if(itr && cy[itr-1] >= b) continue;
            cx[itr] = a; cy[itr] = b;
        }
    }
    int ans = 0;
    rep(i,q){
        if(cx[i]==MOD) break;
        ans++;
    }
    cout << ans << endl;
    return 0;
}