SELECT TYPE FROM ship WHERE flag  =  'Panama' INTERSECT SELECT TYPE FROM ship WHERE flag  =  'Malta'
What types of ships have both ships that have Panama Flags and Malta flags?
[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);