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.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.*;

public class VisTrain {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        ArrayList<Order> list = new ArrayList<Order>();
        while (n-- > 0) {
            list.add(new Order(in.nextInt(), in.nextInt()));
        }
        Collections.sort(list);
        int r = 0;
        int count = 0;
        for (Order obj : list) {
            if (obj.l > r) {
                r = obj.r;
                count++;
            }
        }
        System.out.println(count);
    }

    public static class Order implements Comparable<Order> {

        int l = 0;
        int r = 0;

        public Order(int a, int b) {
            l = a;
            r = b;
        }

        @Override
        public int compareTo(Order t) {
            if (this.r == t.r) {
                return this.l - t.l;
            } else {
                return this.r - t.r;
            }
        }

    }
}

  	 		 	   	 	 	 	 	   		 	   	