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.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;

public class B {
    static class Order implements Comparable<Order> {
        int r, l;

        Order(int a, int b) {
            r = a;
            l = b;
        }

        @Override
        public int compareTo(Order arg0) {
            return Integer.compare(l, arg0.l);
        }

    }

    public static void main(String[] args) throws Exception {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(bf.readLine());
        String[] l;
        Order[] arr = new Order[n];
        for (int i = 0; i < n; i++) {
            l = bf.readLine().split(" ");
            arr[i] = new Order(Integer.parseInt(l[0]), Integer.parseInt(l[1]));
        }
        Arrays.sort(arr);
        int res = 1;
        int lastL = arr[0].l;
        for (int i = 1; i < arr.length; i++) {
            if (arr[i].r > lastL){
                res++;
                lastL = arr[i].l;
            }
        }
        System.out.println(res);
    }
}
