题目中的 $\LaTeX$ 炸了？

修正：

说明/提示

In the first test case you can perform the following operations: $\color{red}{\texttt{WBW}}\texttt{WWB} \to \texttt{WWW}\color{red}{\texttt{WWB}} \to \texttt{WWWWWW}$

In the second test case you can perform the following operations: $\texttt{WW}\color{red}{\texttt{BWB}}\texttt{WW} \to \texttt{WWWWWWW}$

In the third test case you can perform the following operations: $\texttt{B}\color{red}{\texttt{WBWB}} \to \color{red}{\texttt{BWWW}}\texttt{W} \to \texttt{WWWWW}$