CF706A Beru-taxi

Vasiliy lives at point $ (a,b) $ of the coordinate plane. He is hurrying up to work so he wants to get out of his house as soon as possible. New app suggested $ n $ available Beru-taxi nearby. The $ i $ -th taxi is located at point $ (x_{i},y_{i}) $ and moves with a speed $ v_{i} $ . Consider that each of $ n $ drivers will move directly to Vasiliy and with a maximum possible speed. Compute the minimum time when Vasiliy will get in any of Beru-taxi cars.

The first line of the input contains two integers $ a $ and $ b $ ( $ -100

Print a single real value — the minimum time Vasiliy needs to get in any of the Beru-taxi cars. You answer will be considered correct if its absolute or relative error does not exceed $ 10^{-6} $ . Namely: let's assume that your answer is $ a $ , and the answer of the jury is $ b $ . The checker program will consider your answer correct, if .

In the first sample, first taxi will get to Vasiliy in time $ 2 $ , and second will do this in time $ 1 $ , therefore $ 1 $ is the answer. In the second sample, cars $ 2 $ and $ 3 $ will arrive simultaneously.