#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
//#include<bits/stdc++.h>
#include<cstdio>
#include<algorithm>
using namespace std;
typedef long long ll;
#define rep(i, n) for(int i = 0; i < (n); i++)
#define rep1(i, n) for(int i = 1; i <= (n); i++)
#define co(x) cout << (x) << "\n"
#define cosp(x) cout << (x) << " "
#define ce(x) cerr << (x) << "\n"
#define cesp(x) cerr << (x) << " "
#define pb push_back
#define mp make_pair
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define Would
#define you
#define please

const int cm = 1 << 17;
char cn[cm], * ci = cn + cm, ct;
inline char getcha() {
	if (ci - cn == cm) { fread_unlocked(cn, 1, cm, stdin); ci = cn; }
	return *ci++;
}
inline int getint() {
	int A = 0;
	if (ci - cn + 16 > cm) while ((ct = getcha()) >= '0') A = A * 10 + ct - '0';
	else while ((ct = *ci++) >= '0') A = A * 10 + ct - '0';
	return A;
}

void pakuri_sort(int N, ll A[]) {
	const int b = 9;
	ll tmp[100001];
	rep(k, 4) {
		int kazu[1 << b] = {}, kazu2[1 << b] = {};
		rep(i, N) kazu[A[i] >> k * b & ((1 << b) - 1)]++;
		rep(i, (1 << b) - 1) kazu[i + 1] += kazu[i];
		for (int i = N - 1; i >= 0; i--) tmp[--kazu[A[i] >> k * b & ((1 << b) - 1)]] = A[i];
		k++;
		rep(i, N) kazu2[tmp[i] >> k * b & ((1 << b) - 1)]++;
		rep(i, (1 << b) - 1) kazu2[i + 1] += kazu2[i];
		for (int i = N - 1; i >= 0; i--) A[--kazu2[tmp[i] >> k * b & ((1 << b) - 1)]] = tmp[i];
	}
}

int main() {
	//cin.tie(0);
	//ios::sync_with_stdio(false);

  getint();getint();
	int N = getint();
	ll HW[100000];
	rep(i, N) {
		HW[i] = ((ll)getint() << 18) + 100000 - getint();
	}
	pakuri_sort(N, HW);

	int dp[100000];
	int k = 0;
	int saidai = 0;
	const int m = (1 << 18) - 1;
	rep(i, N) {
		int h = 100000 - (HW[i] & m);
		if (saidai < h) {
			dp[k++] = h;
			saidai = h;
		}
		else {
			auto itr = lower_bound(dp, dp + k, h);
			if (itr == dp + k - 1) saidai = h;
			*itr = h;
		}
	}

	printf("%d", k);

	Would you please return 0;
}