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: The dose of CYA per body surface area was calculated for all patients and the patients were divided into two groups based on daily CYA dose : Group 1 , CYA less than or equal to 1 . 55 g / m2 / d ; Group 2 , CYA greater than 1 . 55 g / m2 / d .
### Output Text:
The dose of <span class="chemical">CYA</span> per body surface area was calculated for all patients and the patients were divided into two groups based on daily <span class="chemical">CYA</span> dose : Group 1 , <span class="chemical">CYA</span> less than or equal to 1 . 55 g / m2 / d ; Group 2 , <span class="chemical">CYA</span> greater than 1 . 55 g / m2 / d . 