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.PriorityQueue;
import java.util.Queue;
import java.util.Scanner;
 
public class Main {
	public static class order implements Comparable<order>{
		long l;
		long r;
		public order(long l,long r){
			this.l = l;
			this.r = r;
		}
		@Override
		public int compareTo(order o) {
			// TODO Auto-generated method stub
			return Long.compare(this.l, o.l);
		}
 
	}
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		Queue<order> orders = new PriorityQueue<order>();
		for(int i=0;i<n;i++){
			orders.add(new order(sc.nextLong(),sc.nextLong())) ;
		}
		long min = orders.remove().r;
		int count =1;
		while(!orders.isEmpty()){
			order curr = orders.remove();
			if(curr.l>min){
                                 count++;
                                 min = curr.r;
                        }
			if(curr.r<min)min = curr.r;
		}
		System.out.println(count);
	}
}