Vertical bracket alongside two matrices

Question

How can I draw a curly bracket on the right side of these two vertically stacked matrices?

Here's the MWE for the matrices:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\begin{document}
$$
X = \begin{bmatrix}
x & \cdots & x\
\vdots & \ddots & \vdots\
x & \cdots & x
\end{bmatrix}
$$
$$
Y = \begin{bmatrix}
y & \cdots & y\
\vdots & \ddots & \vdots\
y & \cdots & y
\end{bmatrix}
$$
\end{document}

Answer 1

\documentclass{article}
\usepackage{amsmath}
\begin{document}
[
\left.
\begin{aligned}
X &= \begin{bmatrix}
x & \cdots & x\
\vdots & \ddots & \vdots\
x & \cdots & x
\end{bmatrix}
\
Y &= \begin{bmatrix}
y & \cdots & y\
\vdots & \ddots & \vdots\
y & \cdots & y
\end{bmatrix}
\end{aligned}x
\right}Z
]
\end{document}