On the Subject of Warning Signs

It's much easier to not screw up if you haven't screwed up already.

DANGER! This module shows a large sign to warn you about a specific hazard. To disarm the module, detach the sign by unscrewing its screws, one at a time, when the last seconds digit of the countdown timer is a valid digit.

Get three valid timer digits by following these steps:

  1. Construct a triangle as shown in the diagram by filling in the digits 0 to 9. Start with the first digit of the serial number at the top and continue in reading order, increasing each subsequent digit by 1. Wrap back to 0 if you exceed 9.
  2. Receive a number from Table SGN by using the hazard shown on the sign and the correct column following these rules:
    • If the number of unsolved* modules is a multiple of 4 use column D.
    • Otherwise, if the number of unsolved* modules is a multiple of 3 use column A.
    • Otherwise, if the number of unsolved* modules is a multiple of 2 use column N.
    • Otherwise, use column G.

    * this includes needy modules.

  3. In the triangle, find all possible equilateral triangles in which the received number appears in a corner position. Then, locate the three numbers that don't appear in corner positions of these triangles.

Unscrewing a screw is valid if the last seconds digit of the countdown timer matches one of these three numbers.

NOTE: Make sure to unscrew one screw for every valid timer digit. Moreover, the whole process cannot exceed 9 timer ticks from the first unscrew. Taking too long or unscrewing on an invalid timer digit will result in a strike.

Table SGN: Warning Sign Reference

Hazards1 D A N G
General warning <!> 1 8 3 7
Flammable material <flames> 6 7 2 8
Radioactive material <three segments of a circle around a dot> 3 0 7 6
Toxic material <skull> 7 2 5 3
High temperature <thermometer> 9 5 4 0
Low temperature <snowflake> 2 5 3 4
Mind your head <person bumping their head> 3 4 9 5
High voltage <lightning bolt> 0 1 9 7
Irritant <X> 7 8 1 3
Explosive substance <bursting object with speed lines> 6 4 7 2
Biohazard <the one you know from any 2000s zombie related media> 6 8 1 5
Laser beam <circle emitting rays> 2 7 4 0
Hazardous to the environment <dead tree and fish bones> 0 2 3 6
Corrosive substance <liquid dripping on a hand and a surface> 8 6 9 2
Rotating parts <hand in gears> 0 4 8 5
Deep water <person above water line> 1 4 0 8
Risk of falling <person falling> 9 1 5 6
Cameras <surveillance camera> 1 5 9 4
Falling objects <falling brick, wrench and hammer> 8 9 2 3
Slippery floor <person slipping> 8 6 1 9

1 The text inside the angle brackets is a description of the sign's iconography.