def main():
    N = int(input())
    P = list(map(int, input().split()))
    ans = 1
    mod = 9
    for p in P:
        if p == 0:
            print(0)
            exit()
        ans *= p
        ans %= mod
    if ans == 0:
        print(9)
    else:
        print(ans)

if __name__ == "__main__":
    main()