  In this paper we completely describe maximal green sequences (MGS) of acyclic
quivers with multiple edges in terms of maximal green sequences of their
multiple edge-free (ME-free) versions. In particular we establish that any MGS
of a quiver must be an ME-free MGS of its ME-free version. For quivers with
oriented cycles our results for acyclic quivers do not apply. However a weaker
result is available under certain conditions.
