#include <algorithm>
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("spectacole.in");
ofstream fout("spectacole.out");
int n, s = 0;
struct Spectacol
{
    int inceput, sfarsit;

    /*istream& operator>>(istream& in, Spectacol& out) {
        in >> out.inceput >> out.sfarsit;
        return in;
    }*/
}spectacole[128];

void citire() {
    fin>>n;
    for (int i = 0; i < n; ++i)
    {
        fin>>spectacole[i].inceput>>spectacole[i].sfarsit;
    }
}

void this_is_your_job_bejan() {
    Spectacol prev = spectacole[0];
    int i = 1;
    //cout << "\n\t\tstart\n";
    while (i < n) {
        if(prev.sfarsit <= spectacole[i].inceput)
        {
            //cout << prev.inceput << ' ' << prev.sfarsit << endl;
            ++s;
            prev = spectacole[i];

        }
        ++i;
    }
    //cout << prev.inceput << ' ' << prev.sfarsit << endl;
    //cout << "\n\t\tend\n";
}

int main()
{
    citire();
    /*for (int i = 0; i < n; i++) {
        cout << spectacole[i].inceput<< ' ' << spectacole[i].sfarsit << endl;
    }cout<<"\n\n";*/
    std::sort(spectacole, spectacole + n, [](const Spectacol& a, const Spectacol& b) -> bool {
        return a.inceput < b.inceput && a.sfarsit < b.sfarsit;
    });
    /*for (int i = 0; i < n; i++) {
        cout << spectacole[i].inceput<< ' ' << spectacole[i].sfarsit << endl;
    }*/
    this_is_your_job_bejan();

    fout << s + 1;

    return 0;
}