29973
RATIONALE : It is widely believed that nicotine withdrawal symptoms appear within a few hours of stopping smoking , but few data exist documenting their emergence in naturalistic settings .
 Chemical: nicotine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: nicotine