#include<bits/stdc++.h>
using namespace std;
struct hd{
  int x,y;	
}a[1001];
bool cmp(hd c,hd d){
	return c.y<d.y;
}
int main(){
    int n,ans=1;
    for(int i=1;i<=n;i++){
    	cin>>a[i].x>>a[i].y;
    }
    int ed=a[1].y;
    for(int i=1;i<=n;i++){
    	if(a[i].x>=ed){
    		ans++;
    		ed=a[i].y;
    	}
    }
    cout<<ans<<endl;
	return 0;
}

/**************************************************************
	Problem: 1372
	User: zengdongxin
	Language: C++
	Result: Wrong Answer
****************************************************************/