In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Rapid reversal of anticoagulation reduces hemorrhage volume in a mouse model of warfarin - associated intracerebral hemorrhage .
### Output Text:
Rapid reversal of anticoagulation reduces hemorrhage volume in a mouse model of <span class="chemical">warfarin</span> - associated intracerebral hemorrhage . 