import java.util.Arrays;
import java.util.Scanner;

public class 冰雹数 {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        long a[]=new long[1000000];

            for (int i = 1; i < a.length; i++) {
                long max=i;
                long n=i;
                while(n!=1) {
                    if(n%2==0) {
                        n/=2;
                        max=Math.max(max, n);
                    }else {
                        n*=3;
                        n++;
                        max=Math.max(max, n);
                    }

                }
                a[i]=max;

            }
//          System.out.println(a[999999]);
        while(sc.hasNext()) {
            int n=sc.nextInt();
            long max=0;
            for (int i = 1; i <=n; i++) {
                max=Math.max(max, a[i]);
            }
            System.out.println(max);

        }


        }       

}