What is the fine-grained topic of the following text: The chief rabbi, also known as the Rishon LeZion, delivered a shiur [lecture] to hundreds of students in the Glueck Beit Midrash, after which he participated in a luncheon with various roshei yeshiva and members of the YU faculty and administration including Rabbi Yona Reiss, Max and Marion Grill Dean of RIETS; Chancellor Rabbi Dr. Norman Lamm, Rosh HaYeshiva; Rabbi Zevulun Charlop, dean emeritus of RIETS; Rabbi Hershel Schachter, Nathan and Vivian Fink Distinguished Professorial Chair in Talmud; and Rabbi Mordechai Willig, Rabbi Dr. Sol Roth Chair in Talmud and Contemporary Halacha, among others. Only return the topic.
Chief Rabbi's lecture and meeting at Glueck Beit Midrash