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 possible contribution of the triazolo group to changes in affective status is discussed .
### Output Text:
The possible contribution of the <span class="chemical">triazolo</span> group to changes in affective status is discussed . 