#include<bits/stdc++.h>
using namespace std;
struct hd{
	int x,y;
}a[200];
bool cmp(hd c,hd d){
//	if(c.y<d.y) return true;
//	else return false;
	return c.y<d.y;
}
int main(){
	int n,ans=1;
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i].x>>a[i].y;
	}
	sort(a+1,a+1+n,cmp);
//	for(int i=1;i<=n;i++){
//		cout<<a[i].x<<" "<<a[i].y<<endl;
//	}
      int e=a[1].y;
      for(int i=2;i<=n;i++){
      	  if(a[i].x>=e){
      	  	ans++;
      	  	e=a[i].y;
      	  }
      }
      cout<<ans;
	return 0;
}

/**************************************************************
	Problem: 1372
	User: hulaoshi
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2080 kb
****************************************************************/