class Index {

    public static void combine(ArrayList<String> teams, ArrayList<String> result, int m) {
        if (result.size() >= m) {
            println(result);
            return;
        }
        for (int i = 0; i < teams.size(); i++) {
            ArrayList<String> newResult = (ArrayList<String>) result.clone();
            newResult.add(teams.get(i));
            ArrayList<String> surplusTeams = new ArrayList(teams.subList(i + 1, teams.size()));
            combine(surplusTeams, newResult, m);
        }
    }

    public static void main(String[] args) throws Exception {
        combine(new ArrayList<>(Arrays.asList("T1", "T2", "T3", "T4")), new ArrayList<>(), 2);
    }
}