(1)For a quiver $A_n$ of arbitrary orientation does there exist a finite sequence of quiver mutations that can mutate it to $A_n$ straight orientation $1\rightarrow 2\rightarrow\cdots\rightarrow n$ or its opposite quiver $1\leftarrow 2\leftarrow\cdots\leftarrow n$?
(2)If the answer to (1) is true, can we make sure all mutations in the procedure are at sources and sinks only? (So that during the process we always have a quiver $A_n$?)