Не могу понять в чем ошибка

BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String s = reader.readLine();
        int sum = 0;
        while (true)
        {
            int a = Integer.parseInt(s);
            sum = sum + a;
            if (a == -1)
            {
                System.out.println(sum);
            break;
            }

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String s = reader.readLine();
        int sum = 0;
        while (true)
        {
            int a = Integer.parseInt(s);
            sum = sum + a;
            if (a == -1)
            {
                System.out.println(sum);
            break;
            }


        }





        //напишите тут ваш код
    }
}

String s = reader.readLine();