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 most common side effect was dry month in 5 cases ( 16 . 7 % ) with 2 cases reporting a moderate degree and 1 case with severe degree .
### Output Text:
The most common side effect was dry month in 5 cases ( 16 . 7 % ) with 2 cases reporting a moderate degree and 1 case with severe degree . 