!pip install jovian --upgrade --quiet

number=int(input())
a=[]
prod=1
max_of_prod=0
while (number!=0):
    digit=number%10
    a.append(digit)
    number=number//10
a.reverse()
for i in range(len(a)-12):
    for j in range(i,i+13):
        prod=prod*a[j]
    if (max_of_prod<=prod):
        max_of_prod=prod
    prod=1
print(max_of_prod)  

1254//10