what are kacky tracks? What is the criteria? Is it short and nearly impossible? Or is it just nearly impossible?
That's one of my favourites:
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
And there are also tracks like this one:
PolyTrack24pdhTeYXnFJIK8rkvEu2skm0lGoxGaTaHhuJHsJ0Ge0P2fno0MSzmzXJVLqSnTVxOFwrGH155aa6rPe4MZeRihquQILdEdCgZa5KpqNLbySXZwImxMIjZdqgBCLLxWeobTUeuR0wFAdsfK5BPRqnuRFGIUiEhKSJbkstLXekK88K1me0B9SEB5ldsfK98PbScZb4540L2q2sVoeOEmWa64Id0xfYfPOiyborLDzUOQbApqFN8jfyiXpiesuNXkzLBTy5VhTr1uoTQDTwe8e7Jp5czvarAWGjVAUD0unTYBR4M2WKOvohh9Cb5N0uM9eWXGekXlcTuB2M9pzuTXyD29qJYfexfWGfn6JeFfBEZOpIiNpae7YUUPXcqZeKtoLnxVEb85ahSLBzR0yQrrw1w7e23rjTeCMwETYKMQAbRfAISOSdcE7NUvufWrofYanw2XhKZqOqhyujKuKETBNBHBFBLBIzGc3Re5IGx2qOQ7pZo3clkhvTb88Xx2JJVzCt6DffJ7Dq3KztWwPy97eUQx7Am6ejsWFvPgJitX5v5UdC2uWtq57bCra1ywzojaH795R2gOJRkbwDIlpnbRC7CDn6CSTCWl6Vfosp0QwjBZJMdWADXGJ7F88evsCW8fvpFvPNcaL47sOyy7S0apfopTBWFdfDiqcTJWote38NgJttee3Qv9ebeBwuKzv2dlh45i6F8skMeBw1SxUtHwTefcjUGFqrttWfPwnjj4yagRUceqX6fTUj0yMdrE0qxfFe72hjfdTYzH82V4UysnXYcvjwmuCZf916IP5E2y1ib65ankHkfroGcVftBwn7RrhpcjuVvps7fuvOOlYg28OyOdpvKe3ZNkFPK34G6d5DuxHo0kmQuxul3zcZn0eUXs3QJPUoQh4C2wszaXeXMZF7fc7JX4Cu8btRX4YjUxM1ikpTXqtfUY3aduG88hGFJVauRv74MY0jG4gHvu3M96iUvTvKkab3OHaUyEpq8ru64t96lpq0M85HSBExYipOf13PiXvxJaGle3AYqD4tG
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