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


public class card_trick {
    public static int count(int N) {
        // Vasiot kod tuka
        int[] spil = new int[51];
        for (int i = 0; i < 51; i++) {
            spil[i] = i + 1;
        }
        int howMany = 0;
        while (true) {
            int[] firstSeven = new int[7];
            int[] secondSeven = new int[7];
            int[] novSpil = new int[51];
            for (int i = 6, j = 0; i >= 0; i--, j++) {  //Prvite 7 vo obraten redosled
                firstSeven[j] = spil[i];
            }
            for (int i = 7, j = 0; i < 14; i++, j++) {  //Vtorite 7 vo obicen redosled
                secondSeven[j] = spil[i];
            }
            for (int i = 14, j = 0; i < 51; i++, j++) { //Setiranje bez odozdole novite karti
                novSpil[j] = spil[i];
            }
            for (int i = 37, j = 0; i < 51; i++, j++) {
                novSpil[i] = secondSeven[j];
                i++;
                novSpil[i] = firstSeven[j];
            }
            howMany++;
            if (novSpil[0] == N)
                return howMany;
            for (int i = 0; i < 51; i++)
                spil[i] = novSpil[i];
        }
    }

    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())));
    }

}