import java.io.File;

public class Direct {

    public static void main(String[] args) {
        File start = new File(".");
        printDirectory(start, "");
    }

    public static void printDirectory(File directory, String indent) {
        System.out.println(indent + directory.getName());
        if (directory.isDirectory()) {
            File[] ans = directory.listFiles();
            for (File s: ans) {
                printDirectory(s, indent + "    ");
            }
        }
    }
}