#include<iostream>
#include<algorithm>
using namespace std;
const  int N=100010;
int n;
struct Range
{
	int l,r;
	bool operator < (const Range &W)const
	{
		return r<W.r;
	}
 }range[N];
 
int main()
{
	scanf("%d",&n);
	for (int i=0;i<n;i++)
	{
		int l,r; 
		scanf("%d%d",&l,&r);
		range[i]={l,r};
	}
	sort(range,range+n);
	int res=0,ed=-2e9;
	for (int i=0;i<n;i++)
	{
		if(range[i].l>ed)
		{
			res++;
			ed=range[i].r;
		}
	 }
	 printf("%d",res); 	
}
 

和题一代码完全一样