N = int(input())
i = 1
z = 0

while i <= N:
	if i % 3 == 0 and i % 5 == 0:
		z += 4
	elif (i % 3 == 0 and i % 5 != 0) or (i % 3 != 0 and i % 5 == 0):
		z += 2
	i += 1

print(z)