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: During the last 2 1 / 2 years , 38 patients with ovarian cancer were treated with a combination of cisplatinum ( CPDD ) , 50 mg / m2 , adriamycin , 30 mg / m2 , cyclophosphamide , 300 mg / m2 , on day 1 ; and hexamethylmelamine ( HMM ) , 6 mg / kg daily , for 14 days .
### Output Text:
During the last 2 1 / 2 years , 38 patients with ovarian cancer were treated with a combination of <span class="chemical">cisplatinum</span> ( <span class="chemical">CPDD</span> ) , 50 mg / m2 , <span class="chemical">adriamycin</span> , 30 mg / m2 , <span class="chemical">cyclophosphamide</span> , 300 mg / m2 , on day 1 ; and <span class="chemical">hexamethylmelamine</span> ( <span class="chemical">HMM</span> ) , 6 mg / kg daily , for 14 days . 