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: Recently , we found that therapy with selegiline and L - dopa was associated with selective systolic orthostatic hypotension which was abolished by withdrawal of selegiline .
### Output Text:
Recently , we found that therapy with <span class="chemical">selegiline</span> and <span class="chemical">L - dopa</span> was associated with selective systolic orthostatic hypotension which was abolished by withdrawal of <span class="chemical">selegiline</span> . 