Convert from story to X unit

Unit Definition (story)
The story is an informal unit of distance equal to the average distance between floors of a building. In British English the spelling is "storey" and the plural is "storeys"; Americans write "story" and "stories." Typically a story equals 10 to 12 feet (3.0-3.6 meters). The origin of this use of the word "story" is not entirely clear, but in medieval times a tier of sculptures or stained glass windows on the front of a cathedral was called a stor(e)y because it usually told a story, and the number of stories was a measure of the size of the building.

Unit Definition (X unit)
The X-unit (symbol xu) is a unit of length formerly used to measure the wavelength of X-rays and gamma rays. The X-unit is approximately 1.0021×10-13 metre. Defined by the Swedish physicist Karl Manne Georg Siegbahn (1886-1978) in 1925, the X-unit could not at that time be measured directly; the definition was instead made in terms of the spacing between planes of the calcite crystals used in the measuring apparatus.