#include <bits/stdc++.h>

using namespace std;
void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main() {
    fast_io();
    int n, m, q;
    cin >> n >> m >> q;
    vector<vector<bool>> is_ok(n + 1, vector<bool>(m + 1));
    for (int i = 0; i < q; i++) {
        int a, b;
        cin >> a >> b;
        is_ok[a][b] = true;
    }
    vector<vector<int>> dp(n + 1, vector<int>(m + 1));
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            dp[i][j] = max(
                {dp[i][j - 1], dp[i - 1][j], dp[i - 1][j - 1] + is_ok[i][j]});
        }
    }
    cout << dp[n][m] << endl;
}