import java.util.Scanner;

class Main {
    public static void main(String[] args){
        Scanner stdIn = new Scanner(System.in);
        int N = stdIn.nextInt();

        long sum = 0;

        for(int i = 1; i<=N; i++){
            if(i%3 != 0 && i%5 != 0){
                sum+=i;
            }
        }
        System.out.print(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