помогите
package com.javarush.task.task04.task0442;
/*
Суммирование
*/
import java.io.*;
import java.util.*;
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader buff = new BufferedReader(new InputStreamReader(System.in));
int sum = 0;
while (true) {
int a = Integer.parseInt(buff.readLine());
if (a != -1)
sum = a + sum;
else
sum = a + sum;
System.out.println(sum);
break;
}
}
}