3 quavers in 
The FE and IE version resulted from a misunderstanding of the Chopinesque notation of harmonic legato, in which the moments the particular notes should be played are determined by the regular semiquaver pattern, while the rhythmic values in the additional "voices" are only meant to show how long the particular notes are to be held, creating transitory chords; the values are not to be considered linearly.
Compare the passage in the sources »
category imprint: Differences between sources
issues: FE revisions,
notation: Rhythm