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# (Mono-mcs 6.8.0.105) (judge verdict: Accepted)

using System;
using System.Linq;
using System.Text;
using System.Collections;
using System.Collections.Generic;

namespace AtCoder
{
	class Program
	{
		static void Main(string[] args)
		{
			long n = ReadLineLong();
			long sum = 0;
			for (long i = 1; i <= n; i++)
			{
				if (!(i % 3 == 0 || i % 5 == 0)) sum += i;
			}
			Console.WriteLine(sum);
		}

		public static int nCm(int n, int m)
		{
			if (n == 0) return 0;
			if (m == 0) return 1;
			return n * nCm(n - 1, m - 1) / m;
		}

		public static string ReadLine()
		{
			return Console.ReadLine();
		}

		public static int ReadLineInt()
		{
			return int.Parse(ReadLine());
		}

		public static long ReadLineLong()
		{
			return long.Parse(ReadLine());
		}

		public static string[] ReadLineStringSplit(char s = ' ')
		{
			return ReadLine().Split(s).ToArray();
		}

		public static int[] ReadLineIntSplit(char s = ' ')
		{
			return ReadLine().Split(s).Select(x => int.Parse(x)).ToArray();
		}

		public static long[] ReadLineLongSplit(char s = ' ')
		{
			return ReadLine().Split(s).Select(x => long.Parse(x)).ToArray();
		}
	}
}