19550
They are highly specific to theophylline and do not respond to caffeine , which differs in a single methyl group .
 Chemical: theophylline; Chemical: caffeine; Chemical: methyl
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: theophylline, caffeine, methyl 
Answer:
 Chemical: theophylline; Chemical: caffeine; Chemical: methyl