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 albert.codeforces.restaurant597b;

import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        PriorityQueue<int[]> q = new PriorityQueue<>(Comparator.comparingInt(o -> o[1]));
        while (n-- > 0) {
            q.offer(new int[] {scan.nextInt(), scan.nextInt()});
        }
        int ans = 0;
        int last = 0;
        while (!q.isEmpty()) {
            int[] cur = q.poll();
            if (last < cur[0]) {
                ans++;
                last = cur[1];
            }
        }
        System.out.println(ans);
    }
}
