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.Scanner;
import java.util.List;
import java.util.ArrayList;
import java.util.Collections;
public class Sdsd{

    public static class pair  {
        public int first;
        public int second;
        public pair(int a, int b) {
            this.first=a;
            this.second=b;
        }
    
    }
    public static void main(String[] args) {
        int n;
        Scanner sc=new Scanner(System.in);
        n=sc.nextInt();
        List<pair> list = new ArrayList<pair>();
        for (int i=0; i<n; i++){
            list.add(new pair(sc.nextInt(), sc.nextInt()));
        }
        Collections.sort(list, (o1, o2) -> o1.second - o2.second);
        int ans = 0;
        int last = 0;
        for (int i=0; i<n; i++){
            if (list.get(i).first > last){
                ans++;
                last = list.get(i).second;
            }
        }
        System.out.println(ans);
        
    }
    
}