# Read the input
K = int(input())

# Define the prime and composite numbers
primes = [2, 3, 5, 7, 11, 13]
composites = [4, 6, 8, 9, 10, 12]
composite_set = set(composites)

# Check for edge cases
if K == 0 or K > 156:
    print("0.000000000000000000")
else:
    count = 0
    for p in primes:
        if K % p == 0:
            c = K // p
            if c in composite_set:
                count += 1
    probability = count / 36
    # Print with 18 decimal places
    print("{0:.18f}".format(probability))