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
public class Main {
    public static void main(String[] args) {
        java.util.Scanner scanner = new java.util.Scanner(System.in);
        int reserve = scanner.nextInt(), accept = 1, check = 0;
        Time[] time = new Time[reserve];
        for (int i = 0; i < reserve; i++)
            time[i] = new Time(scanner.nextInt(), scanner.nextInt());
        java.util.Arrays.sort(time, java.util.Comparator.comparing(Time::getTime1));
        for ( int i = 0; i < reserve; i++) {
            if (time[i].time0 > time[check].time1) {
                check = i; accept++; }
        }
        System.out.print(accept);
    }
    public static class Time {
        public int time0, time1;
        public Time (int start, int end) {
            time0 = start; time1 = end;
        }
        public int getTime1(){
            return time1;
        }
    }
}