import java.util.Scanner;

class Main {
	public static void main(String... args){
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		long somma = 0;
		for(int i=1; i<=N; ++i){
			if(i%3!=0 && i%5!=0) somma+=i;
		}
		System.out.print(somma);
	}
}

/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