Keko has $N$ dots in a 2-D coordinate plane. He wants to measure the gap between the most distant two dots. To make the problem easier, Keko decided to change each dot's $\boldsymbol{x}$ or $y$ coordinate to zero.

Help Keko calculate the distance!

Input Format

The first line contains an integer, $N$, the number of dots.

The next $N$ lines each contain the integer coordinates of the dots in $(x,y)$ fashion.

Constraints

$2\leq N\leq10^6$

$-10^9\leq x_i,\ y_i\leq10^9$

It is guaranteed that all dots are distinct, and either their $\boldsymbol{x}$ or $y$ coordinate is equal to $0$.

Output Format

Print the distance between the most distant dots with an absolute error of, at most, $\mathbf{10^{-6}}$.

Sample Input
4
-1 0
1 0
0 1
0 -1

Sample Output
2.000000

Explanation

In the sample, the most distant dots are located at $(-1,0)$ and $(1,0)$.

The distance between them is $2$.

见题面

见题面