from decimal import*

l=Decimal(eval(input()))

ans=(l/3)**3

print(ans)

l=float(eval(input()))

ans=(l/3)**3

print(ans)

from decimal import *

l = Decimal(eval(input()))
ans = (l / 3) ** 3
print(ans)

l = float(eval(input()))
ans = (l / 3) ** 3
print(ans)

-from decimal import * - -l = Decimal(eval(input())) +l = float(eval(input()))