Problem B

def s_b():
    t = int(input())
    arr = []
    for i in range(t):
        n = int(input())
        a = [int(x) for x in input().split()]
        s = sum(a) % n
        inc = (n-s) * s
        arr.append(inc)
    for el in arr:
        print(el)
# s_b()