407989: GYM102961 C Ferris Wheel

There are $$$n$$$ children who want to go to a Ferris wheel, and your task is to find a gondola for each child.

Each gondola may have one or two children in it, and in addition, the total weight in a gondola may not exceed $$$x$$$. You know the weight of every child.

What is the minimum number of gondolas needed for the children?

The first input line contains two integers $$$n$$$ and $$$x$$$: the number of children and the maximum allowed weight.

The next line contains $$$n$$$ integers $$$p_1,p_2,\dots,p_n$$$: the weight of each child.

Constraints:

• $$$1 \le n \le 2\cdot 10^5$$$
• $$$0 \le x \le 10^9$$$
• $$$1 \le p_i \le x$$$

Print one integer: the minimum number of gondolas.

4 10
7 2 3 9

3