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 herein report the case of a 70 - year - old man with 5 - FU - induced cardiotoxicity , in whom a high serum level of alpha - fluoro - beta - alanine ( FBAL ) was observed .
### Output Text:
We herein report the case of a 70 - year - old man with <span class="chemical">5 - FU</span> - induced cardiotoxicity , in whom a high serum level of <span class="chemical">alpha - fluoro - beta - alanine</span> ( <span class="chemical">FBAL</span> ) was observed . 