Reorder days into src

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+--- Part Two ---
+
+All this drifting around in space makes you wonder about the nature of the universe.  Does history
+really repeat itself?  You're curious whether the moons will ever return to a previous state.
+
+Determine the number of steps that must occur before all of the moons' positions and velocities
+exactly match a previous point in time.
+
+For example, the first example above takes 2772 steps before they exactly match a previous point in
+time; it eventually returns to the initial state:
+
+After 0 steps:
+pos=<x= -1, y=  0, z=  2>, vel=<x=  0, y=  0, z=  0>
+pos=<x=  2, y=-10, z= -7>, vel=<x=  0, y=  0, z=  0>
+pos=<x=  4, y= -8, z=  8>, vel=<x=  0, y=  0, z=  0>
+pos=<x=  3, y=  5, z= -1>, vel=<x=  0, y=  0, z=  0>
+
+After 2770 steps:
+pos=<x=  2, y= -1, z=  1>, vel=<x= -3, y=  2, z=  2>
+pos=<x=  3, y= -7, z= -4>, vel=<x=  2, y= -5, z= -6>
+pos=<x=  1, y= -7, z=  5>, vel=<x=  0, y= -3, z=  6>
+pos=<x=  2, y=  2, z=  0>, vel=<x=  1, y=  6, z= -2>
+
+After 2771 steps:
+pos=<x= -1, y=  0, z=  2>, vel=<x= -3, y=  1, z=  1>
+pos=<x=  2, y=-10, z= -7>, vel=<x= -1, y= -3, z= -3>
+pos=<x=  4, y= -8, z=  8>, vel=<x=  3, y= -1, z=  3>
+pos=<x=  3, y=  5, z= -1>, vel=<x=  1, y=  3, z= -1>
+
+After 2772 steps:
+pos=<x= -1, y=  0, z=  2>, vel=<x=  0, y=  0, z=  0>
+pos=<x=  2, y=-10, z= -7>, vel=<x=  0, y=  0, z=  0>
+pos=<x=  4, y= -8, z=  8>, vel=<x=  0, y=  0, z=  0>
+pos=<x=  3, y=  5, z= -1>, vel=<x=  0, y=  0, z=  0>
+
+Of course, the universe might last for a very long time before repeating.  Here's a copy of the
+second example from above:
+
+<x=-8, y=-10, z=0>
+<x=5, y=5, z=10>
+<x=2, y=-7, z=3>
+<x=9, y=-8, z=-3>
+
+This set of initial positions takes 4686774924 steps before it repeats a previous state! Clearly,
+you might need to find a more efficient way to simulate the universe.
+
+How many steps does it take to reach the first state that exactly matches a previous state?
+
+