00:difficulty: easy
01:difficulty: easy
02:difficulty: easy
03:difficulty: easy
04:difficulty: easy
05:difficulty: easy
06:difficulty: easy
07:difficulty: easy
08:difficulty: easy
09:difficulty: intermediate
0A:difficulty: intermediate
0B:difficulty: intermediate
0C:difficulty: intermediate
0D:difficulty: intermediate
0E:difficulty: medium
0F:difficulty: medium
10:difficulty: medium