#include <bits/stdc++.h>
using namespace std;

using ll = long long;
const ll INF = 1LL << 62;

int lis(const vector<int>& a) {
    int n = (int)a.size();

    vector<int> ranks(n);
    vector<ll> dp(n, INF);

    for (int i = 0; i < n; i++) {
        ranks[i] = lower_bound(dp.begin(), dp.end(), a[i]) - dp.begin();
        dp[ranks[i]] = a[i];
    }

    return *max_element(ranks.begin(), ranks.end()) + 1;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, M, Q;
    cin >> N >> M >> Q;

    vector<pair<int, int>> xs;
    xs.reserve(Q);

    for (int i = 0; i < Q; i++) {
        int A, B;
        cin >> A >> B;
        --A;
        --B;
        xs.emplace_back(A, B);
    }

    sort(xs.begin(), xs.end(), [](const auto& lhs, const auto& rhs) {
        if (lhs.first != rhs.first) return lhs.first < rhs.first;
        return lhs.second > rhs.second;
    });

    vector<int> seq;
    seq.reserve(Q);

    for (auto [a, b] : xs) {
        seq.push_back(b);
    }

    cout << lis(seq) << '\n';

    return 0;
}