CF1915B.Not Quite Latin Square

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.

For example, one possible Latin square is shown below. $$\begin{bmatrix} \texttt{A} & \texttt{B} & \texttt{C} \\ \texttt{C} & \texttt{A} & \texttt{B} \\ \texttt{B} & \texttt{C} & \texttt{A} \\ \end{bmatrix}$$

You are given a Latin square, but one of the letters was replaced with a question mark $\texttt{?}$. Find the letter that was replaced.

拉丁方阵是一个 $3 \times 3$ 的网格，由字母 $\texttt{A}$、$\texttt{B}$ 和 $\texttt{C}$ 构成，满足以下条件：

• 在每一行中，字母 $\texttt{A}$、$\texttt{B}$ 和 $\texttt{C}$ 各出现一次；
• 在每一列中，字母 $\texttt{A}$、$\texttt{B}$ 和 $\texttt{C}$ 各出现一次。

例如，一个可能的拉丁方阵如下所示：

$$\begin{bmatrix} \texttt{A} & \texttt{B} & \texttt{C} \\ \texttt{C} & \texttt{A} & \texttt{B} \\ \texttt{B} & \texttt{C} & \texttt{A} \\ \end{bmatrix}$$

你被给定一个拉丁方阵，但其中有一个字母被替换成了问号 $\texttt{?}$。请找出被替换的字母。

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 $\texttt{?}$.

输入的第一行包含一个整数 $t$（$1 \leq t \leq 108$），表示测试用例的数量。

每个测试用例包含三行，每行由三个字符组成，表示一个拉丁方阵。每个字符为 $\texttt{A}$、$\texttt{B}$、$\texttt{C}$ 或 $\texttt{?}$ 中的一个。

每个测试用例均为一个拉丁方阵，其中恰好有一个字母被替换为问号 $\texttt{?}$。

For each test case, output the letter that was replaced.

对于每个测试用例，输出被替换的字母。

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}

三个测试用例的正确拉丁方阵如下所示：

$$\begin{bmatrix} \texttt{A} & \texttt{B} & \texttt{C} \\ \texttt{C} & \color{red}{\texttt{A}} & \texttt{B} \\ \texttt{B} & \texttt{C} & \texttt{A} \\ \end{bmatrix} \quad \begin{bmatrix} \texttt{B} & \texttt{C} & \texttt{A} \\ \texttt{C} & \texttt{A} & \color{red}{\texttt{B}} \\ \texttt{A} & \texttt{B} & \texttt{C} \\ \end{bmatrix} \quad \begin{bmatrix} \color{red}{\texttt{C}} & \texttt{A} & \texttt{B} \\ \texttt{B} & \texttt{C} & \texttt{A} \\ \texttt{A} & \texttt{B} & \texttt{C} \\ \end{bmatrix}$$