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: Flumazenil - treated patients also performed significantly better on the Finger - to - Nose Test and the recall of pictures shown at the 5 - minute assessment .
### Output Text:
<span class="chemical">Flumazenil</span> - treated patients also performed significantly better on the Finger - to - Nose Test and the recall of pictures shown at the 5 - minute assessment . 