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.*;
import java.io.*;

public class Restaurant597B {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);

		int N = scanner.nextInt();

		Pair[] times = new Pair[N];
		for (int i = 0; i < N; ++i) {
			Pair p = new Pair();
			p.l = scanner.nextInt();
			p.r = scanner.nextInt();
			times[i] = p;
		}

		Arrays.sort(times, (a, b) -> a.r - b.r);

		int m = 0;
		int count = 1;
		for (int i = 1; i < N; i++) {
			if(times[i].l > times[m].r) {
				count++;
				m = i;
			}
		}
		System.out.println(count);
	}

	static class Pair {
		public int l;
		public int r;
	}
}