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 i,n,sum=0,a,b,c,diff1=0,diff2=0,plus=0;
  scanf("%d",&n);
  for(i=1; i<=n; i++)
    sum+=i;
  a = n/3;
  b = n/5;
  c = n/15;
  for(i=1; i<=a; i++)
    diff1 += i*3;
  sum -= diff1;
  
  for(i=1; i<=b; i++)
    diff2 += i*5;
  sum -= diff2;
  
  for(i=1; i<=c; i++)
    plus += i*15;
  sum += plus;
  
  printf("%d",sum);
  return 0;
}