#include<iostream>
#include<cstdio>
#include<algorithm> 
#include<bits/stdc++.h>
using namespace std;
struct  px
{
	int start;
	int finish;
}; 
bool cmp(px x,px y)
{
	return x.finish<y.finish;
}
using namespace std;
int main()
{
	int n,sum=1,mi;
	struct px x[100000];
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>x[i].start>>x[i].finish;
	}
	sort(x+1,x+n+1,cmp);
	mi=x[1].finish;
	int j=1;
	while(j<=n)
	{
		j++;
		if(x[j].start>=mi)
		{
			sum++;
			mi=x[j].finish;
		}	
	}
	cout<<sum<<endl;
	return 0;
}