import java.util.Scanner; public class Test12 { public static void main(String[] args) { Scanner sc =new Scanner(System.in); int n = sc.nextInt(); int res,yushu,res6=0,m; while (n>0){ if (n%8==0){ res=n/8; System.out.println(res); return; } else { yushu = n % 8; res = n / 8; if(yushu % 6 == 0){ res6 =yushu/6; }else { while (yushu % 6 != 0){ m=n-(res-1)*8; yushu = m % 6; res=res-1; if(res<1){ System.out.println(-1); return ; } res6=m/6; } } System.out.println(res+res6); return; } } } }