1986. 지그재그 숫자

package oSWExpertAcademy;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class D2_1986 {
    public static void main(String[]args) {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
            int count = Integer.parseInt(br.readLine());
            for(int i=1; i<=count; i++) {
                int num = Integer.parseInt(br.readLine());
                int sum = 0;
                for(int j=1; j<=num; j++) {
                    if(j%2 == 0) {
                        sum -= j;
                    }else {
                        sum += j;
                    }
                }
                System.out.println("#"+i+" "+sum);
            }
        } catch (NumberFormatException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}