import java.io. *;

public class KB
{
	public static String scan()
	{
     String sc="";
	 try{
		 BufferedReader buf=new BufferedReader(new InputStreamReader(System.in));
		 sc=buf.readLine();
	 }catch(Exception e){
	 }
	 return sc;
	}

	public static int scanint()
	{
		int i;
		try{
			i=Integer.parseInt(scan());

		}catch(Exception e){
			System.out.println("請輸入整數");
			i=scanint();

		}
		return i;
	}
}