def main():
    i = int(input())
    a = 0
    for i in range(1,i+1):
        if  i%3 == 0 and i%5 == 0:
            a += 4
        elif i%3 == 0 or i%5 == 0:
            a += 2
        else:
            a += 0
    print(a)


if __name__ == '__main__':
    main()