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

public class Restaurant {
	public static void main(String[] args) throws NumberFormatException, IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		Interval[] a = new Interval[n];
		for(int i = 0 ; i < n ; i++) {
			String[] in = br.readLine().split("\\s+");
			a[i] = new Interval(Integer.parseInt(in[0]), Integer.parseInt(in[1]));
		}
		Arrays.sort(a);
		int res = 0;
		int foo = -1;
		for(int i = 0 ; i < n ; i++) {
			if(a[i].l > foo) {
				res++;
				foo = a[i].r;
			}
		}
		System.out.println(res);
	}
	static class Interval implements Comparable<Interval> {
		int l, r;
		public Interval(int l, int r) {
			this.l = l;
			this.r = r;
		}
		public int compareTo(Interval o) {
			if(this.r != o.r)
				return this.r-o.r;
			return this.l-o.l;
		}
	}
}
