1918: Robberies

有抱负的抢劫犯罗伊看过很多美国电影，他知道坏人通常会被抓住，通常是因为他们太贪婪。他决定在银行抢劫这一利润丰厚的行业工作一段时间，然后退休到一所大学找一份舒适的工作。

几个月来，罗伊一直在评估各家银行的安全性及其持有的现金数量。他想计算风险，尽可能多地赚钱。

他的母亲奥拉已经决定了被抓的可能性。她觉得，如果他一起抢劫的银行给出的概率低于这个，他就足够安全了。

The aspiring Roy the Robber has seen a lot of American movies, and knows that the bad guys usually gets caught in the end, often because they become too greedy. He has decided to work in the lucrative business of bank robbery only for a short while, before retiring to a comfortable job at a university.

For a few months now, Roy has been assessing the security of various banks and the amount of cash they hold. He wants to make a calculated risk, and grab as much money as possible.

His mother, Ola, has decided upon a tolerable probability of getting caught. She feels that he is safe enough if the banks he robs together give a probability less than this.

第一行输入给出T，即案例数。对于每个场景，第一行输入给出一个浮点数P（Roy需要低于的概率）和一个整数N（他计划的银行数量）。然后跟随N行，其中第j行给出整数Mj和浮点数Pj。
银行j包含百万百万，抢劫银行被抓的概率是Pj。



The first line of input gives T, the number of cases. For each scenario, the first line of input gives a floating point number P, the probability Roy needs to be below, and an integer N, the number of banks he has plans for. Then follow N lines, where line j gives an integer Mj and a floating point number Pj .
Bank j contains Mj millions, and the probability of getting caught from robbing it is Pj .

对于每一个测试用例，输出一条线，该线的最大数量为百万，而被捕获的概率小于设置的限制。
注释和限制
0<T<=100
0.0<=P<=1.0
0<N<=100
0<Mj<=100
0.0<=Pj<=1.0
如果银行被抢劫，它就会破产，你可以假设所有的可能性都是独立的，因为警察的资金非常少。



For each test case, output a line with the maximum number of millions he can expect to get while the probability of getting caught is less than the limit set.
Notes and Constraints
0 < T <= 100
0.0 <= P <= 1.0
0 < N <= 100
0 < Mj <= 100
0.0 <= Pj <= 1.0
A bank goes bankrupt if it is robbed, and you may assume that all probabilities are independent as the police have very low funds.

-李勇周赛