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.*;
import java.io.*;

public class CF {
    public static void main(String[] args) throws IOException {
        //BufferedReader br = new BufferedReader(new FileReader("input.txt"));
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));

        int n = Integer.parseInt(br.readLine());
        Pair[] arr = new Pair[n];
        for (int i = 0; i < n; i++) {
            StringTokenizer st = new StringTokenizer(br.readLine());
            arr[i] = new Pair(Integer.parseInt(st.nextToken()), Integer.parseInt(st.nextToken()));
        }
        Arrays.sort(arr);

        int ret = 1;

        int last = arr[0].r;
        for (int i = 1; i < n; i++) {
            if (arr[i].l > last) {
                last = arr[i].r;
                ret++;
            }
        }

        pw.println(ret);
        pw.close();
    }

    static class Pair implements Comparable<Pair> {
        int l, r;

        public Pair(int l, int r) {
            this.l = l;
            this.r = r;
        }

        @Override
        public int compareTo(Pair o) {
            return r - o.r;
        }
    }
}