This is the 10790th most frequent Russian word.
входной
"Entrance" or "input" (adjective).
In this sentence, 'входной' is used as an adjective describing 'билет', meaning 'admission' or 'entry', indicating the type of ticket.
Входной билет оказался бесплатным.
The admission ticket turned out to be free.
Here, 'входной' modifies 'двери', meaning 'entrance', referring to the door typically used to enter a building.
Она ждала меня у входной двери.
She was waiting for me at the entrance door.
'Входным' is an adjective describing 'тестом', meaning 'entrance' or 'introductory', referring to a test given at the start or as a prerequisite.