trik so karti

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Stack;

// VK 51 KARTA. zima prvi 7, gi prevrtuva, zima karta od prevrtenive i edna od spilot, dodeka ne gi potrosi site 7.

public class card_trick {
    public static int count(int N) {
        // Vasiot kod tuka
        int counter=0;
        Queue<Integer> red = new LinkedList<Integer>();
        Stack<Integer> stek = new Stack<Integer>();
        for (int i = 1; i < 52; i++)
            red.add(i);
        while (red.peek() != N) {
            for (int i = 0; i < 7; i++)
                stek.push(red.poll());
            while (!stek.isEmpty()) {
                red.add(stek.pop());
                red.add(red.poll());
            }
            counter++;
        }
    return counter;
    }

    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())));
    }

}