n = int(input())
P = list(map(int, input().split()))

ans = 1
for p in P:
    if p%9 == 0:
        ans *= 9
    else:
        ans *= p%9
if 0 <= ans <= 8:
    print(ans)
else:
    if ans%9 == 0:
        print(9)
    else:
        print(ans%9)