# [Jelly], <s>15</s> 13 bytes ṛa+ɗ\>TẇM{ʋƝP [Try it online!][TIO-km2rxi4x] [Jelly]: https://github.com/DennisMitchell/jelly [TIO-km2rxi4x]: https://tio.run/##tZQ9bgIxEIUPlC3eu0BuECkFDVooUtBEXCCio6HgABQoN@ACSRspErkFXMThx@OZsWchTWTJ@mR712/mzfh1Np@/pXT42L487DeTx9Hhc/W0@Fl/vz@nr9VxuRun1PeYdj2np6lHd2Z0PK/kGWaHeWY@lXeu47J2HSxMx3KGFbOwfEvHqBiF6TjrNgzHdAzHMBpgNOSIHcOxZAWOWZgm3pZpztDcRXOXxuIZgQNsmDedYcNtZDZiNNwq5aCTNHdxoCLuZxTGDVs1NcfOx5XSulE7D8eioTggq3JSMio3yd9EkaixHmpWNaeqQrWpevVNs6dxavSaK1WveVJHNE6toH/scwxk9y9VE/f/0HvBgKMqQNC3t/qzrkSE74uvxKi6/ZvV9Pkv "Jelly – Try It Online" *-2 removing `ṙ1` because the all-zeros pattern can essentially be ignored--if you flip the last bit off, you already know it's the one that's been on the longest* Takes input as an array of Boolean arrays, and outputs 0 or 1. ``` ɗ\ Cumulatively reduce the input by: ṛ right argument a vectorizing-logical-AND + the vectorized sum of the arguments. ṛa+ɗ\ This turns each 1 into how "long" it's been a 1, consecutively. ʋƝ For each pair of adjacent elements from that result: T are the indices at which > the right is less than the left ẇ a sublist of M{ the maximal indices of the left? P Take the product of the results. ```