import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
public class MainClass {
public static void main(String args[]) {
Pattern p = null;
try {
p = Pattern.compile("Java \\d");
} catch (PatternSyntaxException pex) {
pex.printStackTrace();
System.exit(0);
}
String candidate = "Java 4";
Matcher m = p.matcher(candidate);
if (m != null)
System.out.println(m.find());
}
}