Convert from femtometer to league [nautical]

Unit Definition (femtometer)
a metric unit of length equal to one quadrillionth of a meter.

Unit Definition (league [nautical])
The nautical league is approximately equal to three nautical miles, 1/20 degree, or 5556 meters (metres). Note that it is not equivalent to the portugese, french and spanish measurements of the league. The nautical league is also different from the league defined on land.