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 Restaurants {
	
	public static void main(String[] args) throws NumberFormatException, IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	int n = Integer.parseInt(br.readLine());
	Pair [] res = new Pair[n];
	for(int i=0;i<n;i++)
	{
		String [] sp = br.readLine().split(" ");
		res[i] =new Pair(Integer.parseInt(sp[0]),Integer.parseInt(sp[1]));
	}
	Arrays.sort(res);
	int count = 1;
	int lastTakenIndex = 0;
	for(int i=0;i<res.length;i++) {
		if(res[i].a>res[lastTakenIndex].b) {
			count++;
			lastTakenIndex = i;
		}
	}
	System.out.println(count);
	
	}
	static class Pair implements Comparable<Pair>{
		int a, b;
		Pair(int a, int b){
			this.a = a;
			this.b = b;
		}
		@Override
		public int compareTo(Pair arg0) {
			if(this.b == arg0.b)
				return 0;
			else if(this.b>arg0.b)
				return 1;
			else 
				return -1;
		}
		
	}
}
