public static void main(String[] args) {
  try {
    if (args == null || args.length != 2) {
    System.out.println("Invalid number of arguments. " + args[0] + "<input> <output>");
    return;
  } catch (ArrayIndexOutOfBoundsException e) {
    System.out.println("Invalid number of arguments. " + args[0] + "<input> <output>");
    return;
  }