Latex多张图片公用一个标注(标注是图片)的latex代码

在latex中绘制如图的样式：

latex代码：

\begin{figure*}[htbp]
\centering
\subfigure[1] {
 \label{fig:a}
\includegraphics[width=0.45\columnwidth]{figs/1.pdf}
}
\hspace{0.3in}
\subfigure[2] {
\label{fig:b}
\includegraphics[width=0.45\columnwidth]{figs/2.pdf}
}
\hspace{0.3in}
\subfigure[3] {
\label{fig:b}
\includegraphics[width=0.45\columnwidth]{figs/3.pdf}
}
\includegraphics[width=0.27\columnwidth]{figs/标注.pdf}

\subfigure[4] {
 \label{fig:a}
\includegraphics[width=0.45\columnwidth]{figs/4.pdf}
}
\subfigure[5] {
\label{fig:b}
\includegraphics[width=0.45\columnwidth]{figs/5.pdf}
}
\subfigure[6] {
\label{fig:b}
\includegraphics[width=0.45\columnwidth]{figs/6.pdf}
}
\subfigure[7] {
\label{fig:b}
\includegraphics[width=0.45\columnwidth]{figs/7.pdf}
}
\caption{ Comparison of UAV average Reward with 1(a), 2(b), 3(c), 4(d) 5(e) and 6(f) }
\label{fig}
\end{figure*}