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;

public class Node
{
	class Pair implements Comparable<Pair>
	{
		int x, y;
		Pair(int x,int y)
		{
			this.x=x;
			this.y=y;
		}
		@Override
		public int compareTo(Pair o) {
			
			return y-o.y;
		}
		
	}
	public static void main(String[] args) {
		
	Node node=new Node();
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		Pair[] pairs=new Pair[n];
		for(int i=0;i<n;i++)
		{
			pairs[i]=node.new Pair(sc.nextInt(),sc.nextInt());
		}
		Arrays.sort(pairs);
		int answer=1;
		int previousvalue=pairs[0].y;
		for(int i=1;i<n;i++)
		{
			if(pairs[i].x>previousvalue)
			{
				answer++;
				previousvalue=pairs[i].y;
			}
		}
		System.out.println(answer);
	}
}