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 ActivitySelectionProblemGreedy {
    public static int count(Pair p[],int n)
    {
        int c=1;
        int e=p[0].y;
        for(int i=1;i<n;i++)
        {
            if(p[i].x>e)
            {
                e=p[i].y;
                c++;
            }
        }
        return c;
    }
    public static class Pair implements Comparable<Pair>
    {
        int x,y;
        Pair(int x,int y)
        {
            this.x=x;
            this.y=y;
        }
        public int compareTo(Pair b)
        {
            if(this.y!=b.y)
            return Integer.compare(this.y,b.y);
            else
                return Integer.compare(this.x,b.x);
        }
    }
public static void main(String a[])
{
    Scanner s=new Scanner(System.in);
    int n=s.nextInt();
    int b[]=new int[n];
    int e[]=new int[n];
    Pair p[]=new Pair[n];
    for(int i=0;i<n;i++)
    {
        b[i]=s.nextInt();
        e[i]=s.nextInt();
        Pair c=new Pair(b[i],e[i]);
        p[i]=c;
    }
    Arrays.sort(p);//according to finish time
    int ans=count(p,n);
    System.out.println(ans);
}
}
