ZUFEOJ Home ProblemSet Source/Category Contest Status Ranklist F.A.Qs
Login Register

5733: 坚果

内存限制：256 MB 时间限制：1 S 标准输入输出
题目类型：传统 评测方式：文本比较 上传者：
提交：3 通过：3
提交提交记录统计Web Board

题目描述

  你有一个坚果和很多盒子。这些盒子有一个奇妙的功能：如果你把x（x≥0）除数（可以分割一个盒子的空间条）放进去，你会得到一个盒子，分成x+1部分。
你是极简主义者。因此，一方面，您反对将某个盒子分成 k 个以上的部分。另一方面，您反对将超过 v 个螺母放入盒子的某些部分。如果你想把所有的螺母放在盒子里，并且你有 b 除数，你必须使用的最小盒子数量是多少？
请注意，您需要尽量减少使用的盒子数量，而不是部分。您不必最小化使用的除数数。

You have a nuts and lots of boxes. The boxes have a wonderful feature: if you put x (x≥0) divisors (the spacial bars that can divide a box) to it, you get a box, divided into x+1 sections.
You are minimalist. Therefore, on the one hand, you are against dividing some box into more than k sections. On the other hand, you are against putting more than v nuts into some section of the box. What is the minimum number of boxes you have to use if you want to put all the nuts in boxes, and you have b divisors?
Please note that you need to minimize the number of used boxes, not sections. You do not have to minimize the number of used divisors.
Input
The first line contains four space-separated integers k, a, b, v (2≤k≤1000; 1≤a,b,v≤1000) − the maximum number of sections in the box, the number of nuts, the number of divisors and the capacity of each section of the box.
Output
Print a single integer − the answer to the problem.
Examples
Input 
3 10 3 3
Output 
2
Input 
3 10 1 3
Output 
3
Input 
100 100 1 1000
Output 
1
Note
In the first sample you can act like this:
  • Put two divisors to the first box. Now the first box has three sections and we can put three nuts into each section. Overall, the first box will have nine nuts.
  • Do not put any divisors into the second box. Thus, the second box has one section for the last nut.
In the end we've put all the ten nuts into boxes.
The second sample is different as we have exactly one divisor and we put it to the first box. The next two boxes will have one section each.

输入格式

The first line contains four space-separated integers k, a, b, v (2≤k≤1000; 1≤a,b,v≤1000) − the maximum number of sections in the box, the number of nuts, the number of divisors and the capacity of each section of the box

输出格式

Print a single integer − the answer to the problem.

输入样例 复制 

3 10 3 3

输出样例 复制 

2

数据范围与提示

Input 
3 10 3 3
Output 
2
Input 
3 10 1 3
Output 
3
Input 
100 100 1 1000
Output 
1
Note
In the first sample you can act like this:
  • Put two divisors to the first box. Now the first box has three sections and we can put three nuts into each section. Overall, the first box will have nine nuts.
  • Do not put any divisors into the second box. Thus, the second box has one section for the last nut.
In the end we've put all the ten nuts into boxes.
The second sample is different as we have exactly one divisor and we put it to the first box. The next two boxes will have one section each.

分类标签