The Taipei Metro

A simplified slice of the Taipei Metro, with one branch off the main line:

Stylised subway-map diagram on a white background, drawn with thick coloured lines and small white station dots ringed in teal (#2f8576), station names in dark teal (#16433c). A horizontal blue line (#1565a8) with arrowheads runs left to right through three stations: Taipei Main Station, then Ximen, then Longshan Temple. From the Ximen station a green branch line (#1a8a4a) with arrowheads drops straight down through two more stations: Beimen, then Zhongshan. All arrows point in travel direction, away from Taipei Main Station.

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Question: which stations can you reach from Taipei Main Station, riding in the arrows' direction?