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

class Main {

    static InputStreamReader isr = new InputStreamReader(System.in);
    static BufferedReader in = new BufferedReader(isr);
    static OutputStreamWriter osw = new OutputStreamWriter(System.out);
    static BufferedWriter out = new BufferedWriter(osw);

    static class Range implements Comparable<Range> {
        int l, r;
        public Range(int l, int r) {
            this.l = l;
            this.r = r;
        }

        @Override
        public int compareTo(Range o) {
            return this.l - o.l;
        }
    }

    static int N = 100010;
    static int n, l, r;
    static Range[ ] ranges = new Range[N];

    public static void main(String[] args) throws IOException {
        n = Integer.parseInt(in.readLine());
        for (int i = 0; i < n; i++) {
            String[] strs = in.readLine().split(" ");
            int l = Integer.parseInt(strs[0]);
            int r = Integer.parseInt(strs[1]);
            ranges[i] = new Range(l, r);
        }
        Arrays.sort(ranges, 0, n);
        //总区间个数，当前区间的最右边界
        int cnt = 0, cur = Integer.MIN_VALUE;
        for (int i = 0; i < n; i++) {
            if (i == 0 || ranges[i].l > cur) cnt++;
            cur = Math.max(cur, ranges[i].r);
        }

        out.write(cnt+"");
        in.close();
        isr.close();
        out.flush();
        out.close();
        osw.close();
    }
}