SELECT lead_envoy FROM table_name_10 WHERE ryūkyūan_king = "shō kei" AND mission_type = "congratulation" AND year = 1718
Siapa utusan utama misi ucapan selamat pada 1718 dengan raja Ryūkyūan Shō Kei?
CREATE TABLE table_name_10 (lead_envoy VARCHAR, year VARCHAR, ryūkyūan_king VARCHAR, mission_type VARCHAR)