Given an array of n numbers A₁, A₂, ...A_n,  how many maximum groups I can form from this array, such that the sum of the elements in each group is  ≥ X?

Constraints: N ≤ 10⁶, X ≤ 10⁶,  0 ≤ A_i ≤ X,  Sum of all A_i's  ≤ 10⁶.

For example if Array is

[5, 5, 9, 5, 12, 5] and X is 20. Answer is 2 as we can form 2 groups [5,5,5,5] and [9, 12] such that both groups have sum greater than or equal to 20

I have no idea how to get the optimal solution, Any help is welcome.

Thanks!!