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 JavaApplication226 {

    
    public static void main(String[] args) {
        Scanner sc =new Scanner(System.in);
        int n=sc.nextInt();
        order[] a= new order[n];
        for(int i=0;i<n;i++){
            int b=sc.nextInt();int c= sc.nextInt();
            a[i]=new order(b,c);
        }
        
        Arrays.sort(a);
        
        int res=1;
        int lastL= a[0].till;
        for(int i=1;i<n;i++){
            if(a[i].from>lastL){
                res++;
                
                lastL=a[i].till;
            }
        }
        System.out.println(res);
}

   public static class order implements Comparable<order> {
       int from;int till;  
        public order(int from,int till) {
            this.from=from;this.till=till;
        }
        public int compareTo(order arg){
            return Integer.compare(till, arg.till);
        }
    }
}