# [APL (Dyalog Unicode)], <s>22</s> 17 bytes <!-- language-all: lang-apl --> ∊({⍵+⍳≢⍵}¨+\∘≠⊆⊢) [Try it online!][TIO-kxw9bqjm] [APL (Dyalog Unicode)]: https://www.dyalog.com/ [TIO-kxw9bqjm]: https://tio.run/##SyzI0U2pTMzJT///qG@qp/@jtgkGXFyPeucqBOTnVKZl5uQopOUXKZTmZRaWpirkJhZnc4UC1VRXG9pq6z/q3Wp7aL3ho7aJQFbtoRU6MSD6fxpQwaOOLo1qIE/7Ue/mR52LIPLaMY86ZoQ@6mp71LVI8///NAVDBSMFYy4QDWIB2WCeAQxCZQwNIAgFA@UOrTdFwyYKMGipYAnTDTEbAA "APL (Dyalog Unicode) – Try It Online" Monadic `≠` doesn't work on TIO because it's got an older version of Dyalog APL, so I've defined a function `U` to stand in for that.