Problem:
Score : 200 points

Problem Statement

Let us define the FizzBuzz sequence a_1,a_2,... as follows:

If both 3 and 5 divides i, a_i=\mbox{FizzBuzz}.

If the above does not hold but 3 divides i, a_i=\mbox{Fizz}.

If none of the above holds but 5 divides i, a_i=\mbox{Buzz}.

If none of the above holds, a_i=i.

Find the sum of all numbers among the first N terms of the FizzBuzz sequence.

Constraints

1 \leq N \leq 10^6

Input

Input is given from Standard Input in the following format:

N

Output

Print the sum of all numbers among the first N terms of the FizzBuzz sequence.

Sample Input 1

15

Sample Output 1

60

The first 15 terms of the FizzBuzz sequence are:

1,2,\mbox{Fizz},4,\mbox{Buzz},\mbox{Fizz},7,8,\mbox{Fizz},\mbox{Buzz},11,\mbox{Fizz},13,14,\mbox{FizzBuzz}

Among them, numbers are 1,2,4,7,8,11,13,14, and the sum of them is 60.

Sample Input 2

1000000

Sample Output 2

266666333332

Watch out for overflow.

Solution in C# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;

namespace Sumple1
{
    class MainClass
    {
        static void Main()
        {
            Scanner cin = new Scanner();

            long  n = cin.NextLong();
            long sum = 0;
            for (long i = 1; i <= n; i++)
            {
                if((i%3)==0 & (i%5) == 0)
                {
                    //FizzBuzz
                }else if ((i % 3) == 0)
                {
                    //Fizz
                }else if ((i % 5) == 0)
                {
                    //Buzz
                }
                else
                {
                    sum += i;
                }

            }
            Console.WriteLine(sum);
        }
    }

    class Scanner
    {
        string[] s;
        int i;

        char[] cs = new char[] { ' ' };

        public Scanner()
        {
            s = new string[0];
            i = 0;
        }

        public string Next()
        {
            if (i < s.Length) return s[i++];
            string st = Console.ReadLine();
            while (st == "") st = Console.ReadLine();
            s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
            if (s.Length == 0) return Next();
            i = 0;
            return s[i++];
        }

        public int NextInt()
        {
            return int.Parse(Next());
        }
        public int[] ArrayInt(int N, int add = 0)
        {
            int[] Array = new int[N];
            for (int i = 0; i < N; i++)
            {
                Array[i] = NextInt() + add;
            }
            return Array;
        }

        public long NextLong()
        {
            return long.Parse(Next());
        }

        public long[] ArrayLong(int N, long add = 0)
        {
            long[] Array = new long[N];
            for (int i = 0; i < N; i++)
            {
                Array[i] = NextLong() + add;
            }
            return Array;
        }

        public double NextDouble()
        {
            return double.Parse(Next());
        }


        public double[] ArrayDouble(int N, double add = 0)
        {
            double[] Array = new double[N];
            for (int i = 0; i < N; i++)
            {
                Array[i] = NextDouble() + add;
            }
            return Array;
        }
    }
}