--- Day 4: Ceres Search --- "Looks like the Chief's not here. Next!" One of The Historians pulls out a device and pushes the only button on it. After a brief flash, you recognize the interior of the Ceres monitoring station! As the search for the Chief continues, a small Elf who lives on the station tugs on your shirt; she'd like to know if you could help her with her word search (your puzzle input). She only has to find one word: XMAS. This word search allows words to be horizontal, vertical, diagonal, written backwards, or even overlapping other words. It's a little unusual, though, as you don't merely need to find one instance of XMAS - you need to find all of them. Here are a few ways XMAS might appear, where irrelevant characters have been replaced with .: ..X... .SAMX. .A..A. XMAS.S .X.... The actual word search will be full of letters instead. For example: MMMSXXMASM MSAMXMSMSA AMXSXMAAMM MSAMASMSMX XMASAMXAMM XXAMMXXAMA SMSMSASXSS SAXAMASAAA MAMMMXMMMM MXMXAXMASX In this word search, XMAS occurs a total of 18 times; here's the same word search again, but where letters not involved in any XMAS have been replaced with .: ....XXMAS. .SAMXMS... ...S..A... ..A.A.MS.X XMASAMX.MM X.....XA.A S.S.S.S.SS .A.A.A.A.A ..M.M.M.MM .X.X.XMASX Take a look at the little Elf's word search. How many times does XMAS appear? To begin, get your puzzle input.