def solve():
    M = int(input())
    d = [0] + list(map(int, input().split()))
    
    ans = ""
    for i, d in enumerate(d):
        ans += str(i) * d
    
    ans = int(ans) * 10**9
    ans += (M - ans) % M
    
    print(ans)


T = int(input())
for _ in range(T):
    solve()