#include <iostream>
#include <algorithm>
using namespace std;
const int N=100005;
struct Node{
    int l,r;
    bool operator<(const Node &b)const{
        return r<b.r;
    }
}node[N];
int main()
{
    int n;
    cin>>n;
    for(int i=1;i<=n;i++){
        int l,r;
        cin>>l>>r;
        node[i]={l,r};
    }
    sort(node+1,node+n+1);

    int res=0,ed=-2e9;
    for(int i=1;i<=n;i++){
        if(node[i].l>ed){
            ed=node[i].r;
            res++;
        }
    }
    cout<<res;
    //cout << "Hello world!" << endl;
    return 0;
}