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: CONCLUSIONS : High - dose 5 - FU / FA / MMC is an effective and well - tolerated outpatient regimen for AGC ( objective response rate 54 . 6 % ) .
### Output Text:
CONCLUSIONS : High - dose <span class="chemical">5 - FU</span> / <span class="chemical">FA</span> / <span class="chemical">MMC</span> is an effective and well - tolerated outpatient regimen for AGC ( objective response rate 54 . 6 % ) . 