//Sample18_21.java
class Sample18_21{
    public static void main(String[] args){

      String regex = "abcd.fg";
      System.out.println(regex);
      System.out.println("----------");

      String[] strs = {
        "abcdefg",
        "aabcdefg",
        "abcdxxfg",
        "abcdxf"
      };
      boolean boo;

      for(String str : strs){
        boo = str.matches(regex);
        System.out.println(str + "\t" + boo);
      }
    }
}