def digit(n):
    if n==0:
        return 0
    q=str(n)
    tmp=0
    for i in range(len(q)):
        tmp+=int(q[i])
    if tmp%9!=0:
        tmp%=9
    else:
        tmp=9
    return  tmp

n=int(input())
p=list(map(int,input().split()))
ct=1
for i in range(n):
    if p[i]%9!=0:
        ct*=(p[i]%9)
    elif p[i]==0:
        ct*=0
    else:
        ct*=9
ans=digit(ct)
print(ans)