#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)
#define INF ((1LL<<62)-(1LL<<31))
#define all(a)  (a).begin(),(a).end()
#define rall(a)  (a).rbegin(),(a).rend()
typedef long long ll;
typedef pair<ll,ll> pl;

int main() {
    int n,m,q;
    cin >> n >> m >> q;
    vector<vector<bool>> flag(n,vector<bool> (m,false));
    rep(i,q) {
        int a,b;
        cin >> a >> b;
        a--; b--;
        flag[a][b]=true;
    }  
    vector<vector<int>> dp(n+1,vector<int> (m+1,0));
    rep(i,n) rep(j,m) {
        if(flag[i][j]) dp[i+1][j+1]=dp[i][j]+1;
        else dp[i+1][j+1]=max(dp[i+1][j],dp[i][j+1]);
    }
    cout << dp[n][m] << endl;
    return 0;
}