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: Recovery of tacrolimus - associated brachial neuritis after conversion to everolimus in a pediatric renal transplant recipient - - case report and review of the literature .
### Output Text:
Recovery of <span class="chemical">tacrolimus</span> - associated brachial neuritis after conversion to <span class="chemical">everolimus</span> in a pediatric renal transplant recipient - - case report and review of the literature . 