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: A 61 - year - old man was treated with combination chemotherapy incorporating cisplatinum , etoposide , high - dose 5 - fluorouracil ( 2 , 250 mg / m2 / 24 hours ) and folinic acid for an inoperable gastric adenocarcinoma .
### Output Text:
A 61 - year - old man was treated with combination chemotherapy incorporating <span class="chemical">cisplatinum</span> , <span class="chemical">etoposide</span> , high - dose <span class="chemical">5 - fluorouracil</span> ( 2 , 250 mg / m2 / 24 hours ) and <span class="chemical">folinic acid</span> for an inoperable gastric adenocarcinoma . 