5.9 The International Mathematical Olympiad Problem Selection Committee has 34 countries participating, with each country being represented by a team leader and a deputy leader. Before the meeting, the participants shake hands with each other, but the team leader and deputy leader from the same country do not shake hands. After the meeting, the team leader of the host country asks the participants how many times they shook hands, and the answers received are all different. How many people did the deputy leader of the host country shake hands with?