With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Stockard Channing acted as Betty Rizzo in Grease.
text_B: A single-player video game is a video game where input from only one player is expected throughout the course of the gaming session .. video game. video game. `` Single-player game '' usually refers to a game that can only be played by one person , while `` single-player mode '' usually refers to a particular game mode that is designed to be played by a single-player , though the game also contains modes that can be played by several players simultaneously .. game mode. game mode. The vast majority of modern console games and arcade games are designed so that they can be played by a single-player ; although many of these games have modes that allow two or more players to play -LRB- not necessarily simultaneously -RRB- , very few actually require more than one player for the game to be played .. The Unreal Tournament series is one example of such .. Unreal Tournament. Unreal Tournament
not_related.