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+--- Day 23: Crab Cups ---
+
+The small crab challenges you to a game! The crab is going to mix up some cups, and you
+have to predict where they'll end up.
+
+The cups will be arranged in a circle and labeled clockwise (your puzzle input). For
+example, if your labeling were 32415, there would be five cups in the circle; going clockwise around
+the circle from the first cup, the cups would be labeled 3, 2, 4, 1, 5, and then back to 3 again.
+
+Before the crab starts, it will designate the first cup in your list as the current
+cup. The crab is then going to do 100 moves.
+
+Each move, the crab does the following actions:
+
+
+ - The crab picks up the three cups that are immediately clockwise of the
+current cup. They are removed from the circle; cup spacing is adjusted as necessary to
+maintain the circle.
+ - The crab selects a destination cup: the cup with a label equal to the
+current cup's label minus one. If this would select one of the cups that was just
+picked up, the crab will keep subtracting one until it finds a cup that wasn't just picked up. If at
+any point in this process the value goes below the lowest value on any cup's label, it
+wraps around to the highest value on any cup's label instead.
+ - The crab places the cups it just picked up so that they are immediately clockwise of
+the destination cup. They keep the same order as when they were picked up.
+ - The crab selects a new current cup: the cup which is immediately clockwise of the
+current cup.
+
+
+For example, suppose your cup labeling were 389125467. If the crab were to do merely 10 moves, the
+following changes would occur:
+
+-- move 1 --
+cups: (3) 8  9  1  2  5  4  6  7 
+pick up: 8, 9, 1
+destination: 2
+
+-- move 2 --
+cups:  3 (2) 8  9  1  5  4  6  7 
+pick up: 8, 9, 1
+destination: 7
+
+-- move 3 --
+cups:  3  2 (5) 4  6  7  8  9  1 
+pick up: 4, 6, 7
+destination: 3
+
+-- move 4 --
+cups:  7  2  5 (8) 9  1  3  4  6 
+pick up: 9, 1, 3
+destination: 7
+
+-- move 5 --
+cups:  3  2  5  8 (4) 6  7  9  1 
+pick up: 6, 7, 9
+destination: 3
+
+-- move 6 --
+cups:  9  2  5  8  4 (1) 3  6  7 
+pick up: 3, 6, 7
+destination: 9
+
+-- move 7 --
+cups:  7  2  5  8  4  1 (9) 3  6 
+pick up: 3, 6, 7
+destination: 8
+
+-- move 8 --
+cups:  8  3  6  7  4  1  9 (2) 5 
+pick up: 5, 8, 3
+destination: 1
+
+-- move 9 --
+cups:  7  4  1  5  8  3  9  2 (6)
+pick up: 7, 4, 1
+destination: 5
+
+-- move 10 --
+cups: (5) 7  4  1  8  3  9  2  6 
+pick up: 7, 4, 1
+destination: 3
+
+-- final --
+cups:  5 (8) 3  7  4  1  9  2  6 
+
+In the above example, the cups' values are the labels as they appear moving clockwise around the
+circle; the current cup is marked with ( ).
+
+After the crab is done, what order will the cups be in? Starting after the cup labeled
+1, collect the other cups' labels clockwise into a single string with no extra characters; each
+number except 1 should appear exactly once. In the above example, after 10 moves, the cups clockwise
+from 1 are labeled 9, 2, 6, 5, and so on, producing 92658374. If the crab were to
+complete all 100 moves, the order after cup 1 would be 67384529.
+
+Using your labeling, simulate 100 moves. What are the labels on the cups after cup 1?
+
+