9709: Broken LED Lights

There is an ancient tall building that uses LED light tubes in the elevator to display the floor numbers. However, due to budget constraints for maintenance, the management is trying to reduce the number of floors the elevator can stop at and then discard unnecessary LED light tubes.

Currently, the number of floors the elevator can stop at has been determined, and the task of reducing the LED light tube wiring has been assigned to you. You know that the building has 10^m floors, with floor numbers ranging from $0$ to (10^m-1) and displayed as numbers of length $m$ (which may be left-padded with zeros). For each digit of the floor number, there were originally $7$ light tubes, as shown in the figure below, that would flexibly turn on and off according to the required displayed number.

Now, $n$ floors have been selected to continue supporting stops, and the elevator will only display these $n$ floor numbers while moving and stopping. Your task is to minimize the number of light tubes that need to remain operational so that the on and off states of these tubes can be used to determine which of the $n$ possible numbers the stopping floor corresponds to. Your time is very precious, so please calculate the minimum number of light tubes that need to remain operational as soon as possible.

The first line contains an integer $T$ (1≤T≤1001 \leq T \leq 1001≤T≤100), indicating the number of test cases.
Then follow $T$ test cases. For each test case:
The first line contains two integers $n$ and $m$ ($1\le n\le 100$, $1\le m\le 3$).
The second line contains $n$ distinct integers x1,x2,…,xnx_1, x_2, \ldots, x_nx1,x2,…,xn (0<=x<10^m), representing the selected floor numbers. It is guaranteed that each floor number has exactly $m$ digits.
It is also guaranteed that the sum of $n$ over $T$ test cases does not exceed 10³.

For each test case, output an integer in one line, representing the minimum number of light tubes that need to remain operational.

For the second case of the example, one of the possible solutions is listed below.
The original states:

After reduction: