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 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