21828
The compounds were prepared from Alkylideno / arylideno - bis - ureas .
 Chemical: Alkylideno / arylideno - bis - ureas
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: Alkylideno / arylideno - bis - ureas 
Answer:
 Chemical: Alkylideno / arylideno - bis - ureas