4655
In the first case a caesarean section was done one week after replacement of warfarin with heparin .
 Chemical: warfarin; Chemical: heparin
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: warfarin; Chemical: heparin