T = int(input())
for _ in range(T):
    M = int(input())
    D = [0] + list(map(int, input().split()))
    S = ''
    for i,d in enumerate(D):
        S+=str(i)*d
    S = int(S)
    if S%M==0:
        print(S)
    else:
        S = (S)*10**9+10**9-1
        print(S-(S%M))