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

const int N=5e3+10;
int n,dp[N],len,x,y;
struct Friendly_City{
	int k,l;
}a[N];

bool cmp(Friendly_City x,Friendly_City y)
{
	return x.k<y.k;
}

int main()
{
	cin>>x>>y;
	scanf("%d",&n);
	for(int i=1;i<=n;++i)
	{
		scanf("%d%d",&a[i].k,&a[i].l);
	}
	sort(a+1,a+n+1,cmp);
	dp[++len]=a[1].l;
	for(int i=1;i<=n;++i)
	{
		if(dp[len]<a[i].l)
		{
			dp[++len]=a[i].l;
		}
		else
		{
			int upd=upper_bound(dp+1,dp+len+1,a[i].l)-dp;
			dp[upd]=a[i].l;
		}
	}
	printf("%d",len);
	return 0;
}