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 ProB {
	static int n,ans,mm;
	static Pair[] aa=new Pair[500005];
	static class Pair implements Comparable<Pair>
	{
		int x,y;
		Pair(int a,int b)
		{
			x=a;y=b;
		}
		public int compareTo(Pair p) {
			return this.y-p.y;
		}
	}

	public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		ans=0;n=in.nextInt();
		for(int i=0;i<n;i++)
			aa[i]=new Pair(in.nextInt(),in.nextInt());
		Arrays.sort(aa,0,n);mm=0;
		for(int i=0;i<n;i++)
		{
			if(aa[i].x>mm) { ans++;mm=aa[i].y;}
		}
		System.out.println(ans);
	}
}
