The center coordinate of the circle C is O, the coordinate of O is (0,0) , and the radius is r. P and Q are two points not outside the circle, and PO = QO. You need to find a point D on the circle, which makes $PD + QD$ minimum. Output minimum distance sum.
输入解释
The first line of the input gives the number of test cases T; T test cases follow. Each case begins with one line with r : the radius of the circle C. Next two line each line contains two integers x , y denotes the coordinate of P and Q.
Limits $T \leq 500000$ $-100 \leq x , y \leq 100$ $1 \leq r \leq 100$
输出解释
For each case output one line denotes the answer. The answer will be checked correct if its absolute or relative error doesn't exceed $10^{-6}$. Formally, let your answer be a, and the jury's answer be b. Your answer is considered correct if $\frac{|a-b|}{max(1,b)} \leq 10^{-6}$.