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.*;
public class Main{
	public static class Pair implements Comparable<Pair>{
            	public int l,r;
            	public Pair(int al,int ar){
            	    l = al;
            	    r = ar;
            	}	
            	public int compareTo(Pair pair){
		    if(this.r < pair.r)
            	        return -1;
            	    else if(this.r == pair.r)
            	        return 0;
            	    else
            	        return 1;
            	}
	}
	public static void main (String[] args) {
		Scanner sc=new Scanner(System.in);
		int k=sc.nextInt();
		Pair[]arr=new Pair[k];
		for(int i=0;i<k;i++){
			arr[i]=new Pair(sc.nextInt(),sc.nextInt());
		}
		Arrays.sort(arr);
		int a = 0;
		int b = 0;
		for (int i = 0; i < k; i++) {
			if (arr[i].l > b) {
				a++;
				b = arr[i].r;
			}
		}
		System.out.println(a);
		
	}
}