n=int(input())
s=str()
m=0
for i in range(n+1):
    if i==0:
        continue
    if i%3==0 and i%5==0:
        m=m+4
        #s=s+"FizzBuzz"
    elif i%3==0:
        m=m+2
        #s=s+"Fizz"
    elif i%5==0:
        m=m+2
        #s=s+"Buzz"
    i=i+1    
        
#print(s.count("z"))        
print(m)