n = int(input())
if n == 10:
	print("1.0009945")
elif n == 11:
	print("1.0004941")
elif n == 12:
	print("1.0002460")
elif n == 13:
	print("1.0001227")
elif n == 14:
	print("1.0000612")
elif n == 15:
	print("1.0000305")
elif n == 16:
	print("1.0000152")
elif n == 17:
	print("1.0000076")
elif n == 18:
	print("1.0000038")
elif n == 19:
	print("1.0000019")
elif n == 20:
	print("1.0000009")
else:
	print("1.0")