import java.util.*;
class Main
{
	public static void main(String[] args)                                        
	{
		Scanner sc=new Scanner(System.in);
		int t,k,l;
		String p;
		t=sc.nextInt();
		
		l=t/500;
		int a=t%500;
				int ans=l*1000+((a/5)*5);
				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