18907
The Greek military writer Arrian describes these in his book The Art of Military Tactics ( Technē Taktikē ) , and says they originated among the non-Roman cavalry units provided by the allies ( auxilia ) , particularly the Gauls ( that is , the continental Celts ) and Iberians .
 person: Arrian; location: Iberians
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Arrian, Iberians 
Answer:
 person: Arrian; location: Iberians