#include<bits/stdc++.h>
using namespace std;
int n,ans=0,finish=0;
struct contest{
	int l,r;	
}con[10000010];
bool cmp(contest a,contest b){
		    return a.r<=b.r;
}
int main(){
	cin>>n;
	for(int i=1;i<=1;i++)
		cin>>con[i].l>>con[i].r;
		sort(con+1,con+1+n,cmp);
		for(int i=1;i<=n;i++)
			if(finish<=con[i].l)
		ans++,finish=con[i].r;
		cout<<ans<<endl;
	return  0;
}