
115  The 12th Zhejiang University Programming Contest  E
We have a real value x and two infinite sequences A and B. We know that B_{0} = 1. And for each i larger than zero, we know that: For every given A_{0}, define: Now given A_{0} and list of x_{i} which has n elements, calculate the geometric mean of all F(x), thus: InputThe input contains several test cases. For each test case, the first line contains a real value A_{0}(0 < A_{0} < 10000) and an integer n(0 < n < 10000), then the second line contains n real values x_{i}(0 ≤ x_{i} ≤ 30). OutputFor each test case, output a real number as the description required. The relative or absolute error of the answer should not exceed 1e6. Sample Input55.55 1 0.0 12.34 1 1.0 Sample Output55.55 55.304043 Author: FAN, Yuzhe 