1921. Baskets of Gold Coins

单点时限: 2.0 sec

内存限制: 256 MB

You are given N baskets of gold coins. The baskets are numbered from 1 to N. In all except one of the baskets, each gold coin weighs w grams. In the one exceptional basket, each gold coin weighs w-d grams. A wizard appears on the scene and takes 1 coin from Basket 1, 2 coins from Basket 2, and so on, up to and including N-1 coins from Basket N-1. He does not take any coins from Basket N. He weighs the selected coins and concludes which of the N baskets contains the lighter coins. Your mission is to emulate the wizard’s computation.

输入格式

The input file will consist of one or more lines; each line will contain data for one instance of the problem. More specifically, each line will contain four positive integers, separated by one blank space. The first three integers are, respectively, the numbers N, w, and d, as described above. The fourth integer is the result of weighing the selected coins.

N will be at least 2 and not more than 8000. The value of w will be at most 30. The value of d will be less than w.

输出格式

For each instance of the problem, your program will produce one line of output, consisting of one positive integer: the number of the basket that contains lighter coins than the other baskets.

样例

Input
10 25 8 1109
10 25 8 1045
8000 30 12 959879400
Output
2
10
50

61 人解决,83 人已尝试。

73 份提交通过,共有 215 份提交。

4.0 EMB 奖励。

创建: 12 年前.

修改: 2 年,4 月前.

最后提交: 6 天,18 小时前.

来源: Rocky Mountain 2006

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