suppose n integer label 1 n a permutation n integer perm 1indexed consider beautiful arrangement 1 n follow truepermi divisible ii divisible permiGiven integer n return number beautiful arrangement construct Example 1input n 2output 2explanation the beautiful arrangement 12 perm1 1 divisible 1 perm2 2 divisible 2the second beautiful arrangement 21 perm1 2 divisible 1 2 divisible perm2 1example 2Input n 1output 1 Constraints1 n 15