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.math.*;
import java.util.*;


public class Solving {
   public static Scanner in =new Scanner(System.in);
   public static void main(String[] args){
       int n=in.nextInt();
       Order[]z=new Order[n];
       for(int i=0;i<n;i++){
           z[i]=new Order(in.nextInt(),in.nextInt());
       }
       Arrays.sort(z);
       int counter=0;
       int h=-1;
       for(int i=0;i<n;i++){
           if(z[i].l>h){
               counter++;
               h=z[i].r;
           }
       }
       System.out.println(counter);
   }
   public static class Order implements Comparable<Order>{
       int l=0;int r=0;
       public Order(int l,int r){
           this.l=l;
           this.r=r;
          
       }

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