import java.io.*;

// catching Exceptions - if one of the students ct is 0 the program will not crash
// because the predefined Exception is caught

public class testexceptions
{public static input in = new input();
    


public void enter() throws IOException
     {
         for (int x=1; x <=3; x++)  // enter 3 students grades
         {
         int n,sum=0, ct = 0;
         System.out.println("Enter a number or -1 to end");
         n = in.getInt();
           while (n != -1)
             {
              sum += n;
              ct++;
               System.out.println("Enter a number or -1 to end");
            n = in.getInt();
        }
        
  try
   { double avg = sum /ct;
     System.out.println("Average is "+avg);
   }
   catch(ArithmeticException ae)
     {new Exception("Can't divide by zero.");
        }
    }  // for
} // enter

}