At a gathering of friends, every two people who attend the party shake hands once, without repetition or omission. A total of 36 handshakes, how many people attended this party?
一次朋友聚会，参加聚会的人每两人握一次手，不重复、不遗漏．共握手36次，这次聚会共有多少人参加．
<result>9</result>