On the Subject of One-lever combination

It’s only one lever, how hard could it be?

The module is composed of three LEDs, six black squares and a lever. Pulling the lever down will make the squares gradually turn yellow; pulling it up will make them go back to black.

• Determine a five-number sequence using the five steps below.
• Pull the lever down to start inputting the sequence.
• To input a number, flick the lever when that same number of squares are yellow.
• Inputting the incorrect sequence will cause a strike. If the squares are all black again, the input will be reset without causing a strike.
• If the lever is still pulled down when all six squares are yellow, they will all turn black and the lever will be unpulled.

Determining the number sequence

For each of the steps below, follow the instructions to determine a number. Those five numbers make up the sequence to be inputted in order to disarm the module.

Note: the numbers go from 1 to 6, therefore if any number calculated using the steps below is higher than 6, then the number for that step is 6 instead. Similarly, if any number is lower than 1, then the number from that step is 1 instead.

Step 1:

• If the three LEDs are all on or all off, the number is 6.
• Otherwise, if only one LED is on, the number is 4.
• Otherwise, the number is 5.

Step 2:

• If the bottom LED is off and there are at least two batteries on the bomb, the number is the number from Step 1 minus the number of batteries.
• Otherwise, if the top LED is on and there are at least two ports on the bomb, the number is the number from Step 1 minus the number of ports.
• Otherwise, the number is the number from Step 1 minus 3.

Step 3:

• If the last digit on the serial number is odd and there is at least one lit indicator on the bomb, the number is the number from Step 2 plus the number of lit indicators.
• Otherwise, if the serial number contains a vowel and there are at least two unlit indicators on the bomb, the number is the number from Step 2 plus the number of unlit indicators.
• Otherwise, the number is the number from Step 2 plus 2.

Step 4:

• If the number from Step 3 is even, the number is the number from Step 3 minus 3.
• Otherwise, if the number from Step 2 is odd, the number is the number from Step 3 minus 1.
• Otherwise, the number is the number from Step 3 minus 2.

Step 5:

• If all LEDs are off, the number is 5.
• Otherwise, if the middle LED is the only one on or the only one off, the number is 6.
• Otherwise, the number is the sum of the numbers from Step 2 and Step 4.