Not Quite Latin Square
Description
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.
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 $\texttt{?}$.
For each test case, output 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.
3
ABC
C?B
BCA
BCA
CA?
ABC
?AB
BCA
ABC
A
B
C
Note
The correct Latin squares for the three test cases are shown below:
$$\begin{bmatrix} \texttt{A} & \texttt{B} & \texttt{C} \\ \texttt{C} & \color{red}{\texttt{A}} & \texttt{B} \\ \texttt{B} & \texttt{C} & \texttt{A} \\ \end{bmatrix} \quad \begin{bmatrix} \texttt{B} & \texttt{C} & \texttt{A} \\ \texttt{C} & \texttt{A} & \color{red}{\texttt{B}} \\ \texttt{A} & \texttt{B} & \texttt{C} \\ \end{bmatrix} \quad \begin{bmatrix} \color{red}{\texttt{C}} & \texttt{A} & \texttt{B} \\ \texttt{B} & \texttt{C} & \texttt{A} \\ \texttt{A} & \texttt{B} & \texttt{C} \\ \end{bmatrix}$$