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.io.*;
import java.util.*;

public class Codeforces
{
    public static void main(String args[])throws Exception
    {
        BufferedReader bu=new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb=new StringBuilder();
        int n=Integer.parseInt(bu.readLine());
        int i,x,y;
        PriorityQueue<Line> pq=new PriorityQueue<>(new Comparator<Line>() {
            @Override
            public int compare(Line o1, Line o2) {
                if(o1.r>o2.r) return 1;
                else return -1;
            }});

        for(i=0;i<n;i++)
        {
            String s[]=bu.readLine().split(" ");
            x=Integer.parseInt(s[0]); y=Integer.parseInt(s[1]);
            pq.add(new Line(x,y));
        }

        int ans=0,last=0;
        while(!pq.isEmpty())
        {
            Line l=pq.poll();
            if(l.l>last)
            {
                ans++;
                last=l.r;
            }
        }
        System.out.print(ans);
    }

    static class Line
    {
        int l,r;
        Line(int a,int b)
        {
            l=a;
            r=b;
        }
    }
}
