For a string $a_1a_2…a_n$ define the operation $shift$ as
$shift(a_1a_2...a_n)=a_2a_3...a_na_1$
From this, we can define the operation on a language as
$shift(L)=$ {$v:v=shift(w$ for some $w∈L$}
Show that regularity is preserved under the shift operation.