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.*;

/**
 * Created By Nika Doghonadze 11/1/2015.
 */
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int nOrders = sc.nextInt();
        List<Interval> intervalList = new ArrayList<>();
        for (int i=0; i<nOrders; i++){
            intervalList.add(new Interval(sc.nextInt(), sc.nextInt()));
        }
        Collections.sort(intervalList, (o1, o2) -> o1.till - o2.till);

        int res = 0;
        int lastTill = 0;
        for (int i=0; i<nOrders; i++){
            if (intervalList.get(i).from > lastTill){
                res++;
                lastTill = intervalList.get(i).till;
            }
        }
        System.out.println(res);
    }
}

class Interval {
    public int from, till;

    public Interval(int from, int to) {
        this.from = from;
        this.till = to;
    }
}