import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.StringTokenizer;

public class B_19598 {
    static class pair {
        public int start, end;
        pair(int x, int y){
            this.start = x;
            this.end = y;
        }
    }
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int N = Integer.parseInt(br.readLine());

        PriorityQueue<pair> pq = new PriorityQueue<>((e1, e2) ->{
            if(e1.start == e2.start) return e1.end - e2.end;
            return e1.start - e2.start;
        });
        PriorityQueue<Integer> q = new PriorityQueue<>();
        for(int i=0; i<N; i++){
            StringTokenizer st = new StringTokenizer(br.readLine());
            int start = Integer.parseInt(st.nextToken());
            int end = Integer.parseInt(st.nextToken());
            pq.add(new pair(start, end));
        }
        int cnt = 1;
        q.add(pq.poll().end);
        while(!pq.isEmpty()){
            pair next = pq.poll();
            // 꺼낸 회의가 겹칠 때 즉 q의 가장 앞에있는 end값보다 작을 때
            if(next.start < q.peek()){
                cnt++;
            }
            else{
                q.poll();
            }
            q.add(next.end);
        }
        System.out.println(cnt);
    }

}