C. Make It Equaltime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputThere is a toy building consisting of n towers. Each tower consists of several cubes standing on each other. The i-th tower consists of h_i cubes, so it has height h_i.Let's define operation slice on some height H as following: for each tower i, if its height is greater than H, then remove some top cubes to make tower's height equal to H. Cost of one "slice" equals to the total number of removed cubes from all towers.Let's name slice as good one if its cost is lower or equal to k (k \ge n).  Calculate the minimum number of good slices you have to do to make all towers have the same height. Of course, it is always possible to make it so.InputThe first line contains two integers n and k (1 \le n \le 2 \cdot 10^5, n \le k \le 10^9) — the number of towers and the restriction on slices, respectively.The second line contains n space separated integers h_1, h_2, \dots, h_n (1 \le h_i \le 2 \cdot 10^5) — the initial heights of towers.OutputPrint one integer — the minimum number of good slices you have to do to make all towers have the same heigth.ExamplesInput5 53 1 2 2 4Output2Input4 52 3 4 5Output2NoteIn the first example it's optimal to make 2 slices. The first slice is on height 2 (its cost is 3), and the second one is on height 1 (its cost is 4).
Input5 53 1 2 2 4
Output2
['greedy', '*1600']