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("輸入分數(-1結束):");
score = scanner.nextInt();
}
System.out.println("平均:" + (double) sum/count);
}
}