Compare long lists to find missing entries?

[VeganCaramel]

I have two lists (in two text documents).
Each list has a couple thousand entries.
Both lists have almost all the same entries except for a few. List A has three entries that List B doesn't have.
The entries are ordered differently (and randomly) in each list.

Is there a way to have WinMerge report to me which entries exist only in List A and not List B?

In the past I've always used web-based apps for this but I'm tired of uploading sensitive personal files just to perform these comparisons.