#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
int ans=1;
struct cla{
	int a;
	int b;
}t[1000000];
int n;

bool cmp(cla x,cla y){
	return x.b<y.b;
}

int main()
{
	cin>>n;
	for(int i=1;i<=n;i++)
		cin>>t[i].a>>t[i].b;
	sort(t+1,t+n+1,cmp);
	
	int first=t[1].b;
	
	for(int i=2;i<=n;i++)
	{
		if(t[i].a>first)
		{
			ans++;
			first=t[i].b;
		}
	}
	cout<<ans;
	
	
}