import java.util.regex.Pattern;

import java.util.regex.Matcher;

public class RegexMatches {

private static String REGEX = "dog";

  private static String INPUT = "The dog says meow. " + "All dogs say meow.";

   private static String REPLACE = "cat";

   public static void main(String[] args) {

   Pattern p = Pattern.compile(REGEX);

   Matcher m = p.matcher(INPUT);

   INPUT = m.replaceAll(REPLACE);

   System.out.println(INPUT);

   }}