For the definition of the perfect shuffle operation. For languages $A$ and $B,$ let the $\text{perfect shuffle}$ of $A$ and $B$ be the language
$\text{{$w| w = a_{1}b_{1} · · · a_{k}b_{k},$ where $a_{1} · · · a_{k} ∈ A$ and $b_{1} · · · b_{k} ∈ B,$ each $a_{i}, b_{i} ∈ Σ$}}.$
Show that the class of context-free languages is not closed under perfect shuffle.
