import java.io.*;

class Average4
{
// A program that calculates the average of a series of integers. 
// It prompts for each one. A sentinel value is used to indicate the
// end of the series.

 public static void main(String[] args) throws IOException
 {
  BufferedReader in = Text.open(System.in);
  int sum=0,count=1,n;
  System.out.print("Enter number 1 (or -999 to finish): ");
  n=Text.readInt(in);
  while(n!=-999)
     {
      sum+=n;
      count++;
      System.out.print("Enter number "+count+" (or -999 to finish): ");
      n=Text.readInt(in);
     }
  System.out.println("Average is: "+Text.writeDouble((double)sum/(count-1),5,3));
 }
}