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: In order to improve this MMC - dependent schedule we initiated a phase II study with high - dose 5 - FU / FA and 3 - weekly bolus MMC .
### Output Text:
In order to improve this <span class="chemical">MMC</span> - dependent schedule we initiated a phase II study with high - dose <span class="chemical">5 - FU</span> / <span class="chemical">FA</span> and 3 - weekly bolus <span class="chemical">MMC</span> . 