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: Cortical motor overactivation in parkinsonian patients with L - dopa - induced peak - dose dyskinesia .
### Output Text:
Cortical motor overactivation in parkinsonian patients with <span class="chemical">L - dopa</span> - induced peak - dose dyskinesia . 