import java.util.*;
public class Main{
     public static void main(String []args){
         Scanner scan = new Scanner(System.in);
         int a = scan.nextInt();
         
         long b = 0;
         for (int i=1;i<=a;i++){
             if ( i % 3 == 0 || i % 5 == 0 ) continue;
            
             b+=i; 
         }
         
         System.out.println(b);
     }
}
/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