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

class pairs{
    int first;
    int second;
    public pairs(int first,int second){
        this.first = first;
        this.second = second;
    }
}
public class p1803 {
    static int N = 1000005;
    public static void main(String[] args){
        Scanner sc = new Scanner(new BufferedInputStream(System.in));
        int n = sc.nextInt();
        pairs[] pairs = new pairs[N];
        for(int i = 0;i < n;i ++){
            int l = sc.nextInt();
            int r = sc.nextInt();
            pairs[i] = new pairs(l,r);
        }
        Comparator<pairs> comparator = new Comparator<pairs>() {
            @Override
            public int compare(pairs o1, pairs o2) {
                return o1.second - o2.second;
            }
        };
        Arrays.sort(pairs,0,n,comparator);
        int ans = 0;
        int ed = (int)-2e9;
        for(int i = 0;i < n;i ++){
            int l = pairs[i].first;
            int r = pairs[i].second;
            if(l >= ed){
                ans ++;
                ed = r;
            }
        }
        System.out.println(ans);
    }
}