I do not want to post unnice answer… let’s say, it is general and also a way how (sometimes) I solve similar “enigmas”:
YouTube title of video is:
400-ліття Берестейської унії. Літургія у Ватикані.
So it is written in azbuka. If you are familiar with latin letters, you will be probably able to distinguish letters of azbuka and Greek alfabeta. (Chinese or Arab writing would be problem in just reason, I think.) Easily you can find something which says which letter stands for which. This is Ukrainian azbuka, but let’s say we haven’t noticed and now I will rewrite it (as Russian azbuka and so with some mistakes):
400-litt(ja) Berestejc6koj unij. Liturgi(ja) u Vatikani.
I think this answers your question.