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.Arrays;
import java.util.Comparator;
import java.util.Scanner;
public class Main {
    public static class RentTime {
        public int Start;
        public int End;
        public RentTime(int start, int end) {
            Start = start;
            End = end;
        }
        public int getEnd() {
            return End;
        }
    }
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        RentTime[] rentTime = new RentTime[n];
        for (int i = 0; i < n; i++)
            rentTime[i] = new RentTime(scanner.nextInt(), scanner.nextInt());
        Arrays.sort(rentTime, Comparator.comparing(RentTime::getEnd));
        int position = 0, output = 1;
        for (int i = 0; i < n; i++) {
            if (rentTime[i].Start > rentTime[position].End) {
                position = i;
                output++;
            }
        }
        System.out.println(output);
    }
}