#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main()
{
int n;
int brojac=1;
cin>>n;
vector<pair<int, int>>v;
for(int i=0; i<n; i++){
int a;
int b;
cin>>a>>b;
v.push_back(make_pair(b, a));
}
sort(v.begin(), v.end());

    int nd=v[0].first;
    int start=v[0].second;

for(int j=1; j<n; j++){
  int tnd=v[j].first;
  int tstart=v[j].second;
    if(tstart>=nd){
     brojac+=1;
     nd=tnd;
     start=tstart;
    }
}
cout<<brojac;
    return 0;
}