import java.util.Scanner;
//import java.util.Random;

class Main{
	public static void main(String[] args){
		Scanner stdIn=new Scanner(System.in);
		
		final int n=stdIn.nextInt();
		long ans=0;
		for(int i=1;i<=n;++i){
			if(i%3==0 || i%5==0){}
			else ans+=i;
		}
		
		System.out.println(ans);
	}
}
/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