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.*;
import java.io.*;

public class Restaurant597B
{
    public static class Order implements Comparable<Order>
    {
        public int left;
        public int right;

        public Order(int inputleft, int inputright)
        {
            left = inputleft;
            right = inputright;
        }

        public int compareTo(Order other)
        {
            // Order by increasing order of leaving time
            if (this.right != other.right)
                return this.right - other.right;
            else
                return this.left - other.left;
        }
    }
    

    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        // System.out.println("Enter n"); 
        int n = sc.nextInt();
        ArrayList<Order> a = new ArrayList<Order>();
        for (int i=0; i<n; i++)
        {
            // System.out.println("Enter the next left");
            int left = sc.nextInt();
            // System.out.println("Enter the next right");
            int right = sc.nextInt();
            a.add(new Order(left, right));
        }
        Collections.sort(a);
        
        int answer = 1;
        int nextright = a.get(0).right;
        int index = 1;
        boolean done = false;
        while (!done)
        {
            while (index < a.size() && a.get(index).left <= nextright)
            {
                index++;
            }
            if (index == a.size())
            {
                done = true;
            }
            else
            {
                answer++;
                nextright = a.get(index).right;
            }
        }
        System.out.println(answer);
    }
}

        
            
        
        
        
        
        
        
        
            