Editorial for World Tour Contest Problem 1 — Solar Eclipse
Submitting an official solution before solving the problem yourself is a bannable offence.
The input to this program is a list of words in the Irish language, and the expected output has the initial mutation called eclipsis (urú in Irish) applied to the words. This should have been obvious from the image caption "🇮🇪 urú na gréine". For details about how one should apply eclipsis, please see this helpful page on Wiktionary.