CF333E.Summer Earnings

Many schoolchildren look for a job for the summer, and one day, when Gerald was still a schoolboy, he also decided to work in the summer. But as Gerald was quite an unusual schoolboy, he found quite unusual work. A certain Company agreed to pay him a certain sum of money if he draws them three identical circles on a plane. The circles must not interfere with each other (but they may touch each other). He can choose the centers of the circles only from the n options granted by the Company. He is free to choose the radius of the circles himself (all three radiuses must be equal), but please note that the larger the radius is, the more he gets paid.

Help Gerald earn as much as possible.

许多中小学生会在暑假期间寻找工作，而有一天，当杰拉尔德还是一名中学生时，他也决定在暑假打工。但由于杰拉尔德是一名非常特别的中学生，他找到了一份非常特别的工作：某公司同意支付他一笔报酬，条件是他能在平面上画出三个完全相同的圆。这三个圆彼此之间不能相交（但可以互相外切）。他只能从公司提供的 $n$ 个候选位置中选择圆心；至于圆的半径，他可以自由选定（但三个圆的半径必须相等）；请注意：半径越大，他获得的报酬就越多。

请帮助杰拉尔德获得尽可能高的报酬。

The first line contains a single integer n — the number of centers (3 ≤ n ≤ 3000). The following n lines each contain two integers x__i, y__i ( - 104 ≤ x__i, y__i ≤ 104) — the coordinates of potential circle centers, provided by the Company.

All given points are distinct.

第一行包含一个整数 $n$ —— 中心点的数量（$3 \leq n \leq 3000$）。接下来的 $n$ 行每行包含两个整数 $x_i,\,y_i$（$-10^4 \leq x_i,\,y_i \leq 10^4$）—— 公司提供的潜在圆心坐标。

所有给定的点互不相同。

Print a single real number — maximum possible radius of circles. The answer will be accepted if its relative or absolute error doesn't exceed 10 - 6.

输出一个实数——圆的最大可能半径。若答案的相对误差或绝对误差不超过 $10^{-6}$，则视为正确。