Handling xml files with different structures and different names

I have a 开发者_C百科method and I want different users to pass me xml files. These files will have different names for the elements I am looking for and the elements I am looking for maybe at different structures. My first impression was that we should just tell them to pass in the xml in a standard format. However this is how they have their data and they insist that it is much easier if they don't have to convert it.

What can I do to take in data of all types?

Have them pass in a dictionary? number = mydata/numbers

What is the easiest way for them to define their data to me without actually changing it?

sample1

<numbers>
15
</numbers>

sample2

<mydata>
<mynumbers>
15
</mynumbers>
</mydata>

LINQ to XML can handle documents of varying format quite easily. For example this query will get the "15" for both the documents you mentioned:

XDocument doc = XDocument.Load("input.xml");
var result = doc.Descendants().Where(e => e.Name.ToString().Contains("numbers"));