ans = []
t = int(input())
for _ in range(t):
    m = int(input())
    dl = list(map(int, input().split()))
    upper = "".join([str(i + 1) * d for i, d in enumerate(dl)])
    tmp = int(upper + "0" * 9) % m
    lower = str(0 if tmp == 0 else m - tmp).zfill(9)
    res = upper + lower
    ans.append(res)
for an in ans:
    print(an)