import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Call this program with two arguments; a regular expression and a string. The program prints the
 * text, from the string, that matches the first capturing group in the regular expression.
 */
public class RegexExample {
  public static void main(String[] args) {
    String regex = args[0];
    String content = args[1];

    Pattern pat = Pattern.compile(regex);
    Matcher mat = pat.matcher(content);

    if (mat.matches()) {
      System.out.println("Group 1: " + mat.group(1));
    } else {
      System.out.println("No match!");
    }
  }
}
