import java.util.Scanner;
public class Main {
        public static void main(String args[]){
        Scanner sc = new Scanner(System.in);
          
          int N =sc.nextInt();
          long a =0;
          for(int i=1;i<=N;i++){
           if(i%3!=0&&i%5!=0){
             a=a+i;   
           } 
          }
           System.out.print(a);
        }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz