def FizzBuzzString(N):
    cnt = 0
    for i in range(1, N+1):
        if i % 3 == 0:
            cnt += 1
        if i % 5 == 0:
            cnt += 1
    return cnt * 2

if __name__ == '__main__':
    N = int(input())
    print(FizzBuzzString(N))