It is one word "staircase" (open flight of stairs, usually with
rails).
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The open staircase (gaps between the stairs) acts as a chimney
stack that lets the warm air rise to the top floor in winter and
vent out through the windows in summer.
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It is usually called a landing.
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because the previous program is the first one to be interpreted
that's why you need to re run the program to open the current
program that you want to open