题目描述
A Latin square is a $3 \times 3$ grid made up of the letters $\texttt{A}$, $\texttt{B}$, and $\texttt{C}$ such that:
- in each row, the letters $\texttt{A}$, $\texttt{B}$, and $\texttt{C}$ each appear once, and
- in each column, the letters $\texttt{A}$, $\texttt{B}$, and $\texttt{C}$ each appear once.
You are given a Latin square, but one of the letters was replaced with a question mark $\texttt{?}$. Find the letter that was replaced.
Input
The first line of the input contains a single integer $t$ ($1 \leq t \leq 108$) — the number of testcases.
Each test case contains three lines, each consisting of three characters, representing the Latin square. Each character is one of $\texttt{A}$, $\texttt{B}$, $\texttt{C}$, or $\texttt{?}$.
Each test case is a Latin square with exactly one of the letters replaced with a question mark $\texttt{?}$.
Output
For each test case, output the letter that was replaced.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
The correct Latin squares for the three test cases are shown below:
$$\begin{bmatrix} \texttt{A} & \texttt{B} & \texttt{C} \\ \texttt{C} & \color{red}{\texttt{A}} & \texttt{B} \\ \texttt{B} & \texttt{C} & \texttt{A} \\ \end{bmatrix} \quad \begin{bmatrix} \texttt{B} & \texttt{C} & \texttt{A} \\ \texttt{C} & \texttt{A} & \color{red}{\texttt{B}} \\ \texttt{A} & \texttt{B} & \texttt{C} \\ \end{bmatrix} \quad \begin{bmatrix} \color{red}{\texttt{C}} & \texttt{A} & \texttt{B} \\ \texttt{B} & \texttt{C} & \texttt{A} \\ \texttt{A} & \texttt{B} & \texttt{C} \\ \end{bmatrix}$$