p = int(input())

mel = 2**p - 1
mel_bit = bin(mel)
mel_lists = list(mel_bit)
def num_Change(n):
	try:
		return int(n)
	except Exception:
		return 0
		
sets_mel = []
for i in range(len(mel_lists)):
	sets_mel.append(num_Change(mel_lists[i]))
	
print(len(mel_lists) - sets_mel.count(0))