import java.util.Scanner;
 
public class Main { //クラス名はMain
    public static void main(String[] args) {
      Scanner in = new Scanner(System.in);
      int N = in.nextInt();
      long sum = 0;
       for(int i = 1; i <= N; ++i){
           if (!(i % 3 == 0) && !(i % 5 == 0)){
           sum = sum + i;
           }
       }
      System.out.println(sum);
    }
}
/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