Трик со карти

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.NoSuchElementException;

class SLLNode<E> {
    protected E element;
    protected SLLNode<E> succ;

    public SLLNode(E elem, SLLNode<E> succ) {
        this.element = elem;
        this.succ = succ;
    }

    @Override
    public String toString() {
        return element.toString();
    }
}

interface Stack <E>{
    public boolean isEmpty(); //dali stekot e prazen

    public E peek(); // go vrkja elementot na vrvot bez da go izbrishe

    public void clear(); // go brishe stekot

    public void push(E x); //dodava element na vrvot

    public E pop(); //brishe element od vrvot i ni go vrakja istiot
}

class ArrayStack<E> implements Stack<E> {
    private E [] elems; //niza od elementite vo stekot so indeksi [0,depth-1]
    private int depth; //dlabocina na stekot odnosno kolku elementi ke ima

    public ArrayStack(int maxDepth){
        elems=(E[]) new Object [maxDepth]; //maxDepth e maksimalnata golemina na nizata!!! Razlicno od depth shto e momentalna golemina!!!
        depth = 0; //inicijalno bidejki nemame element depth e 0
    }


    @Override
    public boolean isEmpty() {
        return (depth==0); //ako e 0, vrakja true - stekot nema elementi, ako ne stekot ima elementi i vrakja true
    }

    @Override
    public E peek() {
        if(depth==0)
            throw new NoSuchElementException();
        return elems[depth-1]; //ke go vrati posledniot
    }

    @Override
    public void clear() {
        for(int i=0;i<depth;i++){
            elems[i]=null;
        }
        depth=0;
    }

    @Override
    public void push(E x) {
        elems[depth]=x;
        depth++;
    }

    @Override
    public E pop() {
        if(depth==0)
            throw new NoSuchElementException();
        E topmost=elems[--depth];
        elems[depth]=null;
        return topmost;

        /*
        E topmost=elems[depth-1];
        elems[depth-1]=null;
        depth--;
        return topmost;*/
    }
}

interface Queue<E>{
public boolean isEmpty(); // proveruva dali redicata e prazna

public int size(); // ja vrakja dolzinata na redicata

public void clear(); // ja prazni redicata

public E peek(); // ni go dava elementot koj se naogja na pocetokot -front,glava

public void enqueue(E x); // dodava element na krajot na redicata

public E dequeue(); //go brishe elementot na pocetok na redicata i ni ja vrakja negovata vrednost
        }

class LinkedQueue<E> implements Queue<E> {
    private SLLNode<E> front, rear; //front e link do prviot jazel od redicata, rear e link do posledniot jazel od redicata
    private int length; //goleminata na redicata

    public LinkedQueue(){
        clear();
    }

    @Override
    public boolean isEmpty() {
        return (length==0);
    }

    @Override
    public int size() {
        return  length;
    }

    @Override
    public void clear() {
        front=rear=null;
        length=0;
    }

    @Override
    public E peek() {
        if(front==null)
            throw new NoSuchElementException();
        return front.element;
    }

    @Override
    public void enqueue(E x) {
        SLLNode<E> latest = new SLLNode<>(x, null); //pravime nov jazol koj ke go sodrzi xi ke pokazuva na nula
        if (rear != null) { //ako ne stanuva zbor za prv element
            rear.succ = latest;
            rear = latest;
        } else {
            front = rear = latest; // ako e prv element vo listata voedno e i posleden pa i rear i front ke pokazuvaat na nego
        }
        length++;
    }

    @Override
    public E dequeue() {
        if(front!=null){ //ako redicata ima elementi
            E frontmost=front.element;
            front=front.succ; //noviot front e front successor
            if (front == null) { //ama ako naredniot front e null, t.e ako se vadelo eden element a redicata imala samo eden element
                rear=null; //znaci deka i rear e null t.e redicata e prazna!!!
            }
            length--;
            return frontmost;
        }
        else throw new NoSuchElementException();
    }
}

public class card_trick {


    public static int count(int N){

    	LinkedQueue<Integer> shpil = new LinkedQueue<Integer>();
        ArrayStack<Integer> stek = new ArrayStack<Integer>(7);
        int brojac = 0;
        boolean flag = false;

        for(int i=1;i<52;i++) {
            shpil.enqueue(i);
        }

        while (flag == false) {
            for (int i = 0; i < 7; i++) {
                stek.push(shpil.dequeue());
            }

            while (!stek.isEmpty()) {
                shpil.enqueue(stek.pop());
                shpil.enqueue(shpil.dequeue());
            }
            brojac++;
            if (shpil.peek() == N) {
                return brojac;
            }
            flag = false;
        }
   return 0;

	}


	public static void main(String[] args) throws NumberFormatException, IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in) );
		System.out.println(count(Integer.parseInt(br.readLine())));
	}

}