#include<stdio.h>
int main()
{
  int N;
  scanf("%d",&N);
  unsigned long sum=0;
  int i;
  for(i=1;i<N+1;i++){
    if((i%3!=0)&&(i%5!=0)){
      sum=sum+i;
    }
  }
  printf("%lu",sum);
  return 0;
}
