np = number of pages
np = 1 np > 1
orientation units horizontal vertical horizontal vertical
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LANDSCAPE centimeters 26.67 19.05 27.94 20.32*np
inches 10.5 7.5 11.0 8.0*np
PORTRAIT centimeters 19.05 26.67 20.32*np 27.94
inches 7.5 10.5 8.0*np 11.0