import java.io.File;
class FilteredDirectoryTree {
public static void main(String args[]) {
tree(args[0], "txt");
}
public static void tree(String filename, String suffix) {
File file = new File(filename);
if (!file.isDirectory()) {
if (suffix == null || filename.endsWith(suffix))
System.out.println(filename);
return;
}
String files[] = file.list();
for (int i = 0; i < files.length; i++) {
tree(filename + File.separator + files[i], suffix);
}
}
}