import java.io.*;
class test4
{
	public static void main(String[] args) throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		String a=br.readLine();
		String r="";
		int b=Integer.parseInt(a);
		while(b>0)
		{
			r=String.valueOf(b%16>=10?(char)(b%16-10+'A'):(char)(b%16+'0'))+r;
			b=b/16;
		}
		System.out.println(r);	
	}
}