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 (GCC 9.2.1) (judge verdict: Wrong Answer)

#include <stdio.h>
int main (void)
{
  int n, wa1, wa2, wa3, wa4, i, ans;
  scanf("%d", &n);
  wa1 = 0;
  wa2 = 0;
  wa3 = 0;
  wa4 = 0;
  int x, y, z;
  x = n / 3;
  y = n / 5;
  z = n/ 15;
  //合計
  for(i = n;i > 0;i--){
  	wa1 = wa1 + i;
  }
  //3n
  for(i = 0;i <= x;i++){
  	wa2 = wa2 + 3 * i;
  }
  //5n
  for(i = 0;i <= y;i++){
  	wa3 = wa3 + 5 * i;
  }
  //15n
  for(i = 0;i <= z;i++){
  	wa4 = wa4 + 15 * i;
  }
  ans = wa1 - wa2 - wa3 + wa4;
  printf("%d", ans);
  return 0;
}