n = int(input())
P = list(map(int,input().split()))
ans = 1
nine = 0
for p in P:
    if p and p%9 == 0:
        nine = 1
    else:
        ans *= p%9
        ans %= 9
        
if ans:
    print(9 if nine else ans%9)
else:
    print(ans)