import java.util.Scanner;

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

		long sum = 0;
		for(int i=1; i<=N; i++){
			boolean bFizz = false;
			if(i%3==0){
				bFizz = true;
				continue;
			}
			boolean bBuzz = false;
			if(i%5==0){
				bBuzz = true;
				continue;
			}
			sum += i;
		}
		
		System.out.printf("%d\n", 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