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: We report a case of acetazolamide - induced Gerstmann syndrome in a patient with normal renal function , to highlight predisposing factors that are frequently overlooked .
### Output Text:
We report a case of <span class="chemical">acetazolamide</span> - induced Gerstmann syndrome in a patient with normal renal function , to highlight predisposing factors that are frequently overlooked . 