1714D · Color with Occurrences

Problem: You are given some text $t$ and a set of $n$ strings $s_1, s_2, \dots, s_n$.

In one step, you can choose any occurrence of any string $s_i$ in the text $t$ and color the corresponding characters of the text in red. For example, if $t=\texttt{bababa}$ and $s_1=\texttt{ba}$, $s_2=\texttt{aba}$, you can get $t=\color{red}{\texttt{ba}}\texttt{baba}$, $t=\texttt{b}\color{red}{\texttt{aba}}\texttt{ba}$ or $t=\texttt{bab}\color{red}{\texttt{aba}}$ in one step.

You want to color all the letters of the text $t$ in red. When you color a letter in red again, it stays red.

In the example above, three steps are enough:

• Let's color $t[2 \dots 4]=s_2=\texttt{aba}$ in red, we get $t=\texttt{b}\color{red}{\texttt{aba}}\texttt{ba}$;
• Let's color $t[1 \dots 2]=s_1=\texttt{ba}$ in red, we get $t=\color{red}{\texttt{baba}}\texttt{ba}$;
• Let's color $t[4 \dots 6]=s_2=\texttt{aba}$ in red, we get $t=\color{red}{\texttt{bababa}}$.

Each string $s_i$ can be applied any number of times (or not at all). Occurrences for coloring can intersect arbitrarily.

Determine the minimum number of steps needed to color all letters $t$ in red and how to do it. If it is impossible to color all letters of the text $t$ in red, output -1.

Input Format: The first line of the input contains an integer $q$ ($1 \le q \le 100$) —the number of test cases in the test.

The descriptions of the test cases follow.

The first line of each test case contains the text $t$ ($1 \le |t| \le 100$), consisting only of lowercase Latin letters, where $|t|$ is the length of the text $t$.

The second line of each test case contains a single integer $n$ ($1 \le n \le 10$) — the number of strings in the set.

This is followed by $n$ lines, each containing a string $s_i$ ($1 \le |s_i| \le 10$) consisting only of lowercase Latin letters, where $|s_i|$ — the length of string $s_i$.

Output Format: For each test case, print the answer on a separate line.

If it is impossible to color all the letters of the text in red, print a single line containing the number -1.

Otherwise, on the first line, print the number $m$ — the minimum number of steps it will take to turn all the letters $t$ red.

Then in the next $m$ lines print pairs of indices: $w_j$ and $p_j$ ($1 \le j \le m$), which denote that the string with index $w_j$ was used as a substring to cover the occurrences starting in the text $t$ from position $p_j$. The pairs can be output in any order.

If there are several answers, output any of them.

Note: The first test case is explained in the problem statement.

In the second test case, it is impossible to color all the letters of the text in red.