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.*;
import java.io.*;
public class A
{
      public static void main(String ar[]) throws Exception
      {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            int n=Integer.parseInt(br.readLine());
            int a[][]=new int[n][2];
            for(int i=0;i<n;i++)
            {
                  String s1[]=br.readLine().split(" ");
                  a[i][0]=Integer.parseInt(s1[0]);
                  a[i][1]=Integer.parseInt(s1[1]);
            }
            
            Arrays.sort(a,new Comparator<int[]>(){
                  public int compare(final int f1[],final int f2[])
                  {
                        if(f1[1]>f2[1])
                         return 1;
                        else if(f1[1]==f2[1])
                         return 0;
                        else
                         return -1;
                  }
            });
            
            int max=-1;
            int t=0;
            for(int i=0;i<n;i++)
            {
                  if(a[i][0]>max)
                  { t++; max=a[i][1]; }
            }
            System.out.println(t);
      }
}