aaa = input()
ans = ""
num = 0
for i in range(aaa):
  if (i+1)%3 == 0 and (i+1)%5 == 0:
    num = num + 4
  elif (i+1)%3 == 0:
    num = num + 2
  elif (i+3)%5 == 0:
    num = num + 2
print num