import sys
# Pythonのお勉強で書いてみる
k = input()
count = 0
for i in range(1,k+1):
    if i % 3 == 0 and i % 5 == 0:
        count += 4
    elif i % 3 == 0:
        count += 2
    elif i % 5 == 0:
        count += 2
print count