## On the Subject of Add Nauseam

Pop Quiz! I hope you’ve been studying.

Pressing any of the four directional buttons will activate the module.

Once active, the module will begin counting down from 150 seconds and give a series of 20 prompts on the centre screen.

Each of the four directional buttons will display a digit, one of these digits is the correct response to each of the prompts.

The formats of the prompts may be:

- Q#- The correct answer is the last digit of the current question number. The question number itself is hidden when this prompt is given.
- ODD/EVEN- The correct answer is the only one with the displayed parity.
- MIN/MAX- The correct answer is the smallest/largest of the four possible answers.
- X∘#- The correct answer is the result of displayed operation with the previous correct answer substituted into X.
- #∘#- The correct answer is the result of displayed operation.

Take note of the values of the correct answers and the directions of the buttons on which they were displayed. Once all 20 prompts have received correct responses, these will be used to determine the passcode:

- Take the sum of the values and convert it into base 4.
- On the grid of symbols below- start at the centre 2×2 grid.
- For every two button presses in a particular direction, move one space in that direction.
- Take the symbols, in reading order, of the 2×2 grid landed on.

- Take the first occurrences of each letter in the serial number and assign the symbols to each.
- Arrange these letters into alphabetical order and rearrange the symbols accordingly.
- If there are less than four distinct letters in the serial number, apply the above steps to only the first symbols, leaving the last symbols in place.

- The digits 0–3 are encoded as the symbols in the rearranged set from left to right.
- Encode the base 4 digits obtained in step 1 into symbols and enter them into the module.

The entered symbols are submitted into the module when the timer reaches zero. If the submission matches the module's passcode, the module will solve.

The module will reset if:

- A wrong answer is given to a prompt.
- The timer runs out before any symbols are submitted.
- The submission does not match the passcode.