n = int(input())
z_counter=0
for i in range(1,n+1):
    if i%3==0 and i%5==0:
        z_counter = z_counter + 4
    elif i%3 == 0:
        z_counter = z_counter + 2
    elif i%5 == 0:
        z_counter = z_counter + 2
    else:
        pass

print(z_counter)