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.Arrays;
import java.util.Scanner;

public class CF597B{
    static class Interval implements Comparable{
        int left, right;

        public Interval(int left, int right){
            this.left = left;
            this.right = right;
        }

        @Override
        public int compareTo(Object i1){
            return left - ((Interval)i1).left;
        }
    }

    public static void main(String[] args){
        Scanner scn = new Scanner(System.in);
        while (scn.hasNext()){
            int n = scn.nextInt();
            Interval[] allI = new Interval[n];
            int l, r, ans;
            for (int i=0; i<n; i++){
                l = scn.nextInt();
                r = scn.nextInt();
                allI[i] = new Interval(l, r);
            }
            Arrays.sort(allI);
            Interval now = allI[0];
            ans = 1;
            for (int i=1; i<n; i++){
                if (now.right>=allI[i].left){
                    if (now.right>allI[i].right)
                        now = allI[i];
                } else {
                    now = allI[i];
                    ans++;
                }
            }
            System.out.println(ans);
        }
    }
}