Function of declension of numerals for the Russian language?

Question

JavaScript

Good day everyone.
The essence of the question is this: you need to write a function for declining numerals, it takes as input:
a number and 3 words, and returns a word! For example -> A, guest, guest, guests - where A is an integer.
I wrote it, but only up to the number 5, how to "finish" the correctness of the output of the word, for any number that is entered?
(I understand that Math.abs() should be used?)
` var getRightName = function (roomsCount) {
var roomsText = roomsCount + 'rooms';
if (roomsCount === 1) {
roomsText += 'a';
} else if ([2, 3, 4].includes(roomsCount)) {
roomsText += 's';
} else if (roomsCount === 5) {
roomsText = roomsText;
}
return roomsText;
};`