html5 validate same pattern in different inputs

I've been trying to find a more effective way validate inputs with html5. I have several inputs with the same pattern and so far I've copied an pastad the same pattern in each input.

E.G.:

<input type="text" id="foo1" name="bar1" pattern="([a-z]{2}[0-9]{2})"/>
<input type="text" id="foo2" name="bar2" pattern="([a-z]{2}[0-9]{2})"/>
<input type="text" id="foo3" name="bar3" pattern="([a-z]{2}[0-9]{2})"/>
...
<input type="text" id="fooN" name="barN" pattern="([a-z]{2}[0-9]{2})"/>

I want to do it in such a way that I only have the pattern in one place.

Thanks in advance!