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 TestingRound12;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Map.Entry;
import java.util.TreeMap;

public class Restaurant {

	public static void main(String[] args) throws NumberFormatException, IOException {

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		int numOrders = Integer.parseInt(br.readLine());

		Order orders[] = new Order[numOrders];

		String[] parts = null;
		for (int i = 0; i < numOrders; i++) {
			parts = br.readLine().split(" ");
			orders[i] = new Order(Integer.parseInt(parts[0]), Integer.parseInt(parts[1]));
		}

		Arrays.sort(orders);

		int max = 0;
		
		TreeMap<Integer, Integer> map = new TreeMap<Integer, Integer> ();
		for (Order o : orders){
			int tekStart = o .start;
			int tekEnd = o.end;
			int tekMax = 1;
			
			Entry<Integer , Integer> entry = map.lowerEntry(tekStart);
			if (entry!=null){
				tekMax +=entry.getValue();
			}
			
			entry = map.lowerEntry(tekEnd);
			if (entry!=null){
				if (tekMax<entry.getValue()){
					tekMax = entry.getValue();
				}
			}
			
			map.put(tekEnd, tekMax);
			if (max<tekMax){
				max=tekMax;
			}
			
		}
		
		System.out.println(max);
	}
}

class Order implements Comparable<Order> {
	int start;
	int end;

	public Order(int start, int end) {
		this.start = start;
		this.end = end;
	}

	@Override
	public int compareTo(Order o) {
		if (this.end!=o.end)
			return this.end-o.end;
		return 
			this.start-o.start;
	}
}
