```
package com.codegym.task.task05.task0507;
/*
Arithmetic mean
*/
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
int sum = 0;
int count = 0;
int grade = Integer.parseInt(bufferedReader.readLine());
while (grade != -1) {
sum += grade;
count++;
grade = Integer.parseInt(bufferedReader.readLine());
}
double average = (double) sum/count;
System.out.printf("%.1f",average);
}
}
```

package com.codegym.task.task05.task0507;
/*
Arithmetic mean
*/
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
int sum = 0;
int count = 0;
int grade = Integer.parseInt(bufferedReader.readLine());
while (grade != -1) {
sum += grade;
count++;
grade = Integer.parseInt(bufferedReader.readLine());
}
double average = (double) sum/count;
System.out.printf("%.2f",average);
}
}

System.out.printin(average);is enough.