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: FINDINGS : 5408 women were randomised ; participating women have a median follow - up of 46 months for major endpoints .
### Output Text:
FINDINGS : 5408 women were randomised ; participating women have a median follow - up of 46 months for major endpoints . 