71789
Meanwhile , in the Soviet Union , Léon Theremin had been developing a mirror drum-based television , starting with 16 lines resolution in 1925 , then 32 lines and eventually 64 using interlacing in 1926 .
 location: Soviet Union; person: Léon Theremin
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
 Entities: Soviet Union, Léon Theremin 
Answer:
 location: Soviet Union; person: Léon Theremin