import java.util.*;

class Meeting_Hour implements Comparable<Meeting_Hour>{
    public int start;
    public int end;

    Meeting_Hour(int start, int end){
        this.start = start;
        this.end = end;
    }

    public int compareTo(Meeting_Hour another){
        if(this.end == another.end) return this.start - another.start;
        return this.end - another.end;
    }
}

public class _1931 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        ArrayList<Meeting_Hour> meetingList = new ArrayList<>();
        int N = sc.nextInt();
        for(int i=0; i<N; i++){
            meetingList.add(new Meeting_Hour(sc.nextInt(),sc.nextInt()));
        }
        sc.close();

        Collections.sort(meetingList);
        // meetingList.sort((a,b)->{
        //     if(a.end == b.end) return a.start - b.start;
        //     return a.end - b.end;
        // });
        int currentEnd = meetingList.get(0).end;
        int result = 1;
        for(int i=1; i<N; i++){
            if(currentEnd<=meetingList.get(i).start){
                currentEnd = meetingList.get(i).end;
                result++;
            }
        }
        System.out.println(result);
    }
}