import java.io.*;
public class Scorecalculator{
	public static void main(String[] args) {
		String filepath="scores.txt";
		int sum=0;
		int count=0;
		try (BufferedReader br = new BufferedReader(new FileReader(filepath))){
			String line;
			while ((line=br.readLine()) != null) {
				try {
					sum+=Integer.parseInt(line.trim());
					count++;
				} catch (NumberFormatException e){
					System.out.println("数字格式错误，跳过该行："+ line);
				}
			}
			if (count>0){
				double average=(double)sum/count;
				System.out.println("平均分"+average);
			} else {
				System.out.println("没有有效成绩数据");
			}
		} catch (FileNotFoundException e) {
			System.out.println("错误：文件不存在-"+filepath);
		} catch (IOException e) {
			System.out.println("错误，读取文件时发生错误-"+e.getMessage());
		}
	}
}