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.*;
public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner in=new Scanner(System.in);
		int n=in.nextInt();
		//p a=new p();//a为声明的结构体
		p[] arr=new p[n];
		for(int i=0;i<n;i++)
		{	 arr[i]=new p();
			 arr[i].x=in.nextInt();
			 arr[i].y=in.nextInt();			
		}//初始化
		Arrays.sort(arr,new mycmp());//按照结束时间先后排序
		int sum=1;
		int mo=arr[0].y;
		for(int i=1;i<n;i++){
			while(arr[i].x>mo){
				mo=arr[i].y;
			sum++;			
		}
		}
		System.out.println(sum);
	}}
class p{
	int x,y;
}//希望用类似结构体的类实现数组功能
 class mycmp implements Comparator<p>{
	 public int compare(p A,p B)   
	  {  	        
	        return A.y-B.y;  
 
	  }  
}