1986_지그재그 숫자.py

T = int(input())

for i in range(T):
    N = int(input())
    sum = 0
    for j in range(1, N + 1):
        if j % 2 == 0:
            sum -= j
        else:
            sum += j

    print("#%d %d" % (i + 1, sum))