import java.io.*;

public class  DirListing{
	private static void dirlist(String fname){
		File dir = new File(fname);
		String[] chld = dir.list();
		if(chld == null){
			System.out.println("Specified directory does not exist or is not a directory.");
			System.exit(0);
		}else{
			for(int i = 0; i < chld.length; i++){
				String fileName = chld[i];
				System.out.println(fileName);
			}
		}
	}
	public static void main(String[] args){
		switch(args.length){
			case 0: System.out.println("Directory has not mentioned.");
					System.exit(0);
			case 1: dirlist(args[0]);
					System.exit(0);
			default : System.out.println("Multiple files are not allow.");
					  System.exit(0);
		}
	}
}