import java.io.*;

public class Main
{
	public static void main(String[] args)throws IOException
	{
		BufferedReader br =
		new BufferedReader(new InputStreamReader(System.in));
		
		String str=br.readLine();
		long sum=0;
		long num1=Long.parseLong(str);
		
		for(long i=0;i<=num1;i++){
			if(i%3!=0&&i%5!=0){
				sum+=i;
			}
		}
		
		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