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 HelloWorld {


    public static void main (String args[]){
        Scanner in = new Scanner(System.in);

        int n = in.nextInt();
        Pair [] mas = new Pair[n];
        for (int i = 0; i < n; i++) {
            int a = in.nextInt();
            int b = in.nextInt();
            mas[i] = new Pair(a, b);
        }
        Arrays.sort(mas);

        int count = 0;
        //int answer[] = new int[n-1];
        int last = -1;
       
        for (int i = 0; i < n; i++) {
            if(mas[i].second<last)
            {
                last=mas[i].second;
            }
            if(mas[i].first>last)
            {
                count++;
                last=mas[i].second;
            }
        }
        System.out.println(count);

    }
}



class Pair implements Comparable<Pair>
{
    int first;
    int second;
    public Pair(int fi,int se)
    {
        first=fi;
        second=se;
    }
    private int compare(int o1, int o2) {
        return ((Comparable) o1).compareTo(o2);
    }
    public int compareTo(Pair o) {
        int cmp = compare(first, o.first);
        return cmp == 0 ? compare(second, o.second) : cmp;
    }
}
