import java.util.*;
public class Main{
public static void main(String[]args){
Scanner sc=new Scanner(System.in);
  long t=sc.nextLong();
  long total=0;
 for(long i=0;i<=t;i++){
  	if(i%3==0 || i%5==0){
    continue;
    }
    else{
    total+=i;
    }
  }
  System.out.println(total);
}
}

/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