from decimal import Decimal, getcontext

getcontext().prec = 1000  # Set high precision to handle very small numbers accurately

n = int(input())

if n == 0:
    value = Decimal('4.00000000')
else:
    numerator = 3 ** n
    denominator = 4 ** (n - 1)
    value = Decimal(numerator) / Decimal(denominator)

# Format the output to exactly 8 decimal places
formatted_value = format(value, '.8f')
print(formatted_value)