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.Comparator;
import java.util.Scanner;

public class Main {
	
	public static void main(String[] args)
	{
		Scanner s=new Scanner(System.in);
		
		int n=s.nextInt();
		
		pair[] arr=new pair[n];
		
		for(int i=0;i<n;i++)
		{
			int a=s.nextInt();
			int b=s.nextInt();
			
			pair p=new pair(a,b);
			
			arr[i]=p;
		}
		
		Arrays.sort(arr,new comp());
		
		int count=1;
		
		int end=arr[0].r;
		
		for(int i=1;i<n;i++)
		{
			if(arr[i].l>end)
			{
				count++;
				end=arr[i].r;
			}
		}
		
		System.out.println(count);
		
	}
	
}

class pair
{
	int l;
	int r;
	
	public pair(int l,int r)
	{
		this.l=l;
		this.r=r;
	}
}

class comp implements Comparator<pair>
{
	public int compare(pair a,pair b)
	{
		return a.r-b.r;
	}
}