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
//package codeforces;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;

public class Restaurant {

	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		List<int[]> list = new ArrayList<>();
		for (int i = 0; i < n; i++) {
			int[] arr = new int[2];
			arr[0] = in.nextInt();
			arr[1] = in.nextInt();
			list.add(arr);
		}

		Collections.sort(list, (o1, o2) -> {
			Integer x = o1[1];
			Integer y = o2[1];
			return x.compareTo(y);
		});

		int result = 0;
		int last = -1;
		for (int i = 0; i < list.size(); i++) {
			if (i == 0) {
				last = list.get(i)[1];
				result++;
			} else {
				if (list.get(i)[0] > last) {
					last = list.get(i)[1];
					result++;
				}
			}
		}
		System.out.println(result);
		in.close();
	}
}
