for _ in range(int(input())):
    m=int(input())
    D=list(map(int, input().split()))
    tmp=""
    for i,d in enumerate(D,1):
        if d==0:continue
        tmp+=str(i)*d
    tmp=int(tmp)*(10**8)
    if tmp%m!=0:
        tmp+=m-tmp%m
    assert tmp%m==0
    assert tmp<=10**18
    print(tmp)