https://adventofcode.com/2021/day/4

## \--- Day 4: Giant Squid ---

You're already almost 1.5km (almost a mile) below the surface of the ocean,
already so deep that you can't see any sunlight. What you _can_ see, however,
is a giant squid that has attached itself to the outside of your submarine.

Maybe it wants to play
[bingo](https://en.wikipedia.org/wiki/Bingo_\(American_version\))?

Bingo is played on a set of boards each consisting of a 5x5 grid of numbers.
Numbers are chosen at random, and the chosen number is _marked_ on all boards
on which it appears. (Numbers may not appear on all boards.) If all numbers in
any row or any column of a board are marked, that board _wins_. (Diagonals
don't count.)

The submarine has a _bingo subsystem_ to help passengers (currently, you and
the giant squid) pass the time. It automatically generates a random order in
which to draw numbers and a random set of boards (your puzzle input). For
example:

[code]

    7,4,9,5,11,17,23,2,0,14,21,24,10,16,13,6,15,25,12,22,18,20,8,19,3,26,1
    
    22 13 17 11  0
     8  2 23  4 24
    21  9 14 16  7
     6 10  3 18  5
     1 12 20 15 19
    
     3 15  0  2 22
     9 18 13 17  5
    19  8  7 25 23
    20 11 10 24  4
    14 21 16 12  6
    
    14 21 17 24  4
    10 16 15  9 19
    18  8 23 26 20
    22 11 13  6  5
     2  0 12  3  7
    
[/code]

After the first five numbers are drawn (`7`, `4`, `9`, `5`, and `11`), there
are no winners, but the boards are marked as follows (shown here adjacent to
each other to save space):

[code]

    22 13 17 _11_  0         3 15  0  2 22        14 21 17 24  _4_
     8  2 23  _4_ 24         _9_ 18 13 17  _5_        10 16 15  _9_ 19
    21  _9_ 14 16  _7_        19  8  _7_ 25 23        18  8 23 26 20
     6 10  3 18  _5_        20 _11_ 10 24  _4_        22 _11_ 13  6  _5_
     1 12 20 15 19        14 21 16 12  6         2  0 12  3  _7_
    
[/code]

After the next six numbers are drawn (`17`, `23`, `2`, `0`, `14`, and `21`),
there are still no winners:

[code]

    22 13 _17_ _11_  _0_         3 15  _0_  _2_ 22        _14_ _21_ _17_ 24  _4_
     8  _2_ _23_  _4_ 24         _9_ 18 13 _17_  _5_        10 16 15  _9_ 19
    _21_  _9_ _14_ 16  _7_        19  8  _7_ 25 _23_        18  8 _23_ 26 20
     6 10  3 18  _5_        20 _11_ 10 24  _4_        22 _11_ 13  6  _5_
     1 12 20 15 19        _14_ _21_ 16 12  6         _2_  _0_ 12  3  _7_
    
[/code]

Finally, `24` is drawn:

[code]

    22 13 _17_ _11_  _0_         3 15  _0_  _2_ 22        _14_ _21_ _17_ _24_  _4_
     8  _2_ _23_  _4_ _24_         _9_ 18 13 _17_  _5_        10 16 15  _9_ 19
    _21_  _9_ _14_ 16  _7_        19  8  _7_ 25 _23_        18  8 _23_ 26 20
     6 10  3 18  _5_        20 _11_ 10 _24_  _4_        22 _11_ 13  6  _5_
     1 12 20 15 19        _14_ _21_ 16 12  6         _2_  _0_ 12  3  _7_
    
[/code]

At this point, the third board _wins_ because it has at least one complete row
or column of marked numbers (in this case, the entire top row is marked: `_14
21 17 24 4_`).

The _score_ of the winning board can now be calculated. Start by finding the
_sum of all unmarked numbers_ on that board; in this case, the sum is `188`.
Then, multiply that sum by _the number that was just called_ when the board
won, `24`, to get the final score, `188 * 24 = _4512_`.

To guarantee victory against the giant squid, figure out which board will win
first. _What will your final score be if you choose that board?_