> import java.io.*;
> import java.util.*;
> 
> public class Main{
> 	public static void main(String args[]) throws Exception
>         {
> 	    Scanner cin = new Scanner(System.in);		
>              int a1 = cin.nextInt(), 
> 		 a2 = cin.nextInt(),
> 		 a3= cin.nextInt(),
> 		 a4 = cin.nextInt(),
> 		 a5 = cin.nextInt(),
> 		 a6= cin.nextInt(),
> 		 a7 = cin.nextInt(),
> 		 a8 = cin.nextInt(),
> 		 a9 = cin.nextInt(),
> 		 a10 = cin.nextInt(),
> 		 a11= cin.nextInt(),
> 		 a12 = cin.nextInt();
> 	    double temp = (a1+a2+a3+a4+a5+a6+a7+a8+a9+a10+a11+a12)/12;
> 	    System.out.println("$"+temp);
> 	}