import java.util.Scanner;
public class ScoreAverage {
       public static void main(String[] args) {
       Scanner scanner = new Scanner (System.in);       
       int score=0;
       int sum=0;
       int count= -1;
       while (score != -1) {
             count++;
             sum += score;
             System.out.print("write the score: ");
             score =scanner.nextInt();
       }
       System.out.println("average:"+ (double) sum/count);
        }
}