public class Main {
  static final class BatchConfig {
    private final String title;
    private final int count;
    BatchConfig(String title, int count) {
      if (count <= 0) throw new IllegalArgumentException("count must be positive");
      this.title = title;
      this.count = count;
    }
    String describe() { return title + ": " + count; }
  }
  public static void main(String[] args) {
    var config = new BatchConfig("Letters", 3);
    System.out.println(config.describe());
  }
}