#include<fstream>
#include<algorithm>
using namespace std;
struct interval{
        int stanga;
        int dreapta;
    };
bool cmp(interval a,interval b){
    if(a.dreapta==b.dreapta)
        return a.stanga>b.stanga;
    return  a.dreapta<b.dreapta;

}
int main()
{
    ifstream f("int.in");
    ofstream g("int.out");
    int n,sum=1,x;
    f>>n;
interval v[50001];
    for(int i=1;i<=n;++i)
        f>>v[i].stanga>>v[i].dreapta;
    sort(v+1,v+n+1,cmp);
    x=v[1].dreapta;
    for(int i=2;i<=n;++i)
    {
        if(v[i].stanga>=x)
        {
            ++sum;
            x=v[i].dreapta;
        }
    }
    g<<sum;
return 0;
}