import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long FizzBuzz = -1;
        long Buzz = -2;
        long Fizz = -3;
        long sum = 0;
        for(long i = 1; i <= N; i++){
            if(i%3 != 0 && i%5 != 0){
                sum = sum + i;
            }else{

            }
        }
        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