pattern matching for 2 forward slash using regex in java

I would like to do pattern matching for following text in my word file, I am not sure how I can use pattern matcher

(P // TRIF) (P) (U//TRIF) (U)

import java.util.ArrayList;
import java.util.List;
import java.util.regex;
public class ExtractDemo {
public static void main(String[] args) {
        String input = "I have a ( U) but I (P) like my (P//TRIF) better (U//TRIF).";

        Pattern p = Pattern.compile("(P|U|P//TRIF|U//TRIF)");
        Matcher m = p.matcher(input);

        List<String> animals = new ArrayList<String>();
        while (m.find()) {
            System.out.println("Found a " + m.group() + ".");
            animals.add(m.group());
        }
    }
}