#include<bits/stdc++.h>
using namespace std;
int n;
struct id{
	int x,y;
}a[100005];
bool cmp(id i1,id i2){
	return i1.x<i2.x;
}
int main{
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i].x>>a[i].y;
	}
	sort(a+1,a+1+n,cmp);
	now=a[1].y;
	int ans=1;
	for(int i=2;i<=n;i++){
		if(a[i].x>=now){
			now=a[i].y;
			ans++;
		}
	}
	cout<<ans;
	return 0;
}