times = int(input())
multipleList = list()
numberListList = list()

for i in range(times):
    multipleList.append(int(input()))
    numberListList.append(input().split(" "))

for i in range(times):
    multiple = multipleList[i]
    numberList = numberListList[i]

    Y = ""
    for index, numberString in enumerate(numberList):
        buf = str(index+1) * int(numberString)
        Y = Y + buf
    Y = int(Y)
    # print(Y)
    
    r = Y * pow(10,9) % multiple
    Z = 0 if r == 0 else multiple - r

    X = Y * pow(10,9) + Z
    print(X)