SELECT rank FROM captain EXCEPT SELECT rank FROM captain WHERE CLASS  =  'Third-rate ship of the line'
Find the captain rank that has no captain in Third-rate ship of the line class.
[Schema (values) (types)]: | ship_1 |  captain : captain_id (text) , name (number) , ship_id (text) , age (number) , class (text) , rank (text) | Ship : ship_id (text) , name (number) , type (text) , built_year (number) , class (text) , flag (text);