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