//problem no 4
#include<stdio.h>
int main()
{ int n,sum=0,i;
  scanf("%d",&n);
  for(i=1;i<=n;i++)
  {
      if(i%2==0&&i%3==0)//divisible by 2 and 3
        {sum=sum+i;}
  }
  printf("%d\n",sum);
}