#include<bits/stdc++.h>
using namespace std;
int main()
{
vector< pair<int,int> > v;
int noofconf,n,starttime,endtime;
cin>>noofconf;
for(int i = 0 ; i < noofconf ; i++)
{
cin>>starttime>>endtime;
v.push_back(make_pair(starttime,endtime));
}
sort(v.begin(),v.end());
int noofrooms=1;
for(int i = 0 ; i < noofconf ; i++)
{
if(v[i].second > v[i+1].first)
noofrooms++;
}
cout<<noofrooms;
return 0;
}
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