import java.util.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
	int n = sc.nextInt();
    double sum = 0;
    for(int i = 1; i <= n; i++){
      if(i % 3 != 0 && i % 5 != 0){
        sum += i;
      }
    }
    
    System.out.println(String.format("%.0f", 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