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 restaurant;

import java.util.*;
import java.io.*;

public class restaurant {
	public static void main(String[] args) throws IOException {
		BufferedReader fin = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(fin.readLine());
		int[][] orders = new int[n][2];	//start time, end time
		for(int i = 0; i < n; i++) {
			StringTokenizer st = new StringTokenizer(fin.readLine());
			orders[i] = new int[] {Integer.parseInt(st.nextToken()), Integer.parseInt(st.nextToken())};
		}
		Arrays.sort(orders, (a, b) -> a[1] - b[1]);
		int curTime = -1;
		int ans = 0;
		for(int i = 0; i < n; i += 0) {
			while(i < n && orders[i][0] <= curTime) {
				i ++;
			}
			if(i == n) {
				break;
			}
			ans ++ ;
			curTime = orders[i][1];
		}
		System.out.println(ans);
	}
}
