A restaurant received n orders for the rental. Each rental order reserve the restaurant for a continuous period of time, the i-th order is characterized by two time values — the start time li and the finish time ri (li ≤ ri).

Restaurant management can accept and reject orders. What is the maximal number of orders the restaurant can accept?

No two accepted orders can intersect, i.e. they can't share even a moment of time. If one order ends in the moment other starts, they can't be accepted both.

Input

The first line contains integer number n (1 ≤ n ≤ 5·105) — number of orders. The following n lines contain integer values li and ri each (1 ≤ li ≤ ri ≤ 109).

Output

Print the maximal number of orders that can be accepted.

Examples

Input

2
7 11
4 7


Output

1


Input

5
1 2
2 3
3 4
4 5
5 6


Output

3


Input

6
4 8
1 5
4 7
2 5
1 3
6 8


Output

2
import java.util.Arrays;
import java.util.Scanner;

/**
 * Created by fleeon on 12/16/15.
 */
public class P597B {
    static class Reservation implements Comparable {
        int start, end;

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

        @Override
        public int compareTo(Object o) {
            Reservation reservation = (Reservation) o;
            return start == reservation.start ? end - reservation.end : start - reservation.start;
        }

        @Override
        public String toString(){
            return start + " ~ " + end;
        }
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int N = scanner.nextInt();
        Reservation n[] = new Reservation[N];
        for (int i = 0; i < N; i++) {
            n[i] = new Reservation(scanner.nextInt(), scanner.nextInt());
        }
        Arrays.sort(n, 0, N);
//        System.out.println(Arrays.toString(n));
        int C = 1;
        int end = n[0].end;
        for (int i = 1; i < n.length; i++) {
            Reservation reservation = n[i];
            if (reservation.start > end) {
                C++;
                end = reservation.end;
            } else if (reservation.end < end) {
                end = reservation.end;
            }
        }
        System.out.print(C);
    }
}
