九度-题目1433：FatMouse

题目1433：FatMouse时间限制：1 秒内存限制：128 兆特殊判题：否提交：3223解决：1419题目描述：FatMouse prepared M pounds of cat food, ready to trade with the cats guarding the warehouse containing his favorite food, JavaBean.The warehouse has N rooms. The i-th room contains J[i] pounds of JavaBeans and requires F[i] pounds of cat food. FatMouse does not have to trade for all the JavaBeans in the room, instead, he may get J[i]* a% pounds of JavaBeans if he pays F[i]* a% pounds ofcat food. Here a is a real number. Now he is assigning this homework to you: tell him the maximum amount of JavaBeans he can obtain. 输入：The input consists of multiple test cases. Each test case begins with a line containing two non-negative integers M and N. Then N lines follow, each contains two non-negative integers J[i] and F[i] respectively. The last testcase is followed by two -1's. All integers are not greater than 1000.输出：For each test case, print in a single line a real number accurate up to 3 decimal places, which is the maximum amount of JavaBeans that FatMouse can obtain.样例输入：

5 3
7 2
4 3
5 2
20 3
25 18
24 15
15 10
-1 -1

样例输出：

13.333
31.500

英文题，乍看上去有些脑袋发涨，等翻译完再来做。。。

翻译之后的结果是这样的。。。

题目描述：

输入：

输入由多个测试用例组成。每一个测试案例都是以一行包含两个非负整数和N为例，然后每一个包含2个非负整数的。最后一个测试案例是2 - 1的，所有的整数都不大于1000。

输出：

对于每一个测试案例，在一行一个实数精确到小数点后3位的打印，即字母可以获得最大的JavaBeans量。

样例输入：

5 3
7 2
4 3
5 2
20 3
25 18
24 15
15 10
-1 -1

样例输出：

13.333
31.500

示例代码：

4000