Sadly, this is the last time Sean will play James Bond.
His mission is to network antennas that are scattered across a vast desert, which can
be represented as a 2D plane. He will set the transmission radius of each antenna to
be the same non-negative real number
. The range of an antenna is defined as the
set of all points whose distance to the antenna is at most
. If ranges of two antennas
have a common point, those antennas can directly communicate. Also, if antennas
and
can communicate, as well as antennas
and
, then antennas
and
are also
able to communicate, through antenna
.
Sean wants to network the antennas, i.e. make it possible for every two antennas to
communicate. Since M has limited his spending for this mission, and larger radii require
more money, Sean will choose the smallest possible radius . Help him solve this
problem!
Input
The first line contains an integer
, the number of antennas.
Each of the following lines contains integers
and
, coordinates of the
-th antenna.
Output
Output the minimal radius.
Your answer will be considered correct if its absolute or relative error doesn't exceed .
Scoring
In test cases worth points it holds that
.
Sample Input 1
2
1 1
2 2
Sample Output 1
0.7071068
Sample Input 2
7
2 3
3 4
4 5
0 1
3 1
4 2
1 5
Sample Output 2
1.4142135
Explanation for Sample Output 2

Sample Input 3
4
2020 20
20 2020
2020 2020
20 20
Sample Output 3
1000.0000000
Comments