A 10-digit arrangement 0,1,2,3,4,5,6,7,8,9 is called beautiful if (i) when read left to right, 0,1,2,3,4 form an increasing sequence, and 5,6,7,8,9 form a decreasing sequence, and (ii) 0 is not the leftmost digit. For example, 9807123654 is a beautiful arrangement. Determine the number of beautiful arrangements. combinatorics proposedcombinatorics