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

for i in range(n):
    if P[i] == 0:
        print(0)
        exit()
    if P[i] % 9 == 0:
        P[i] = 9
    else:
        P[i] %= 9

ans = 1
for i in range(n):
    ans *= P[i]
    if ans % 9 == 0:
        ans = 9
    else:
        ans %= 9
print(ans)