Problem: Given are N points (x_i, y_i) in a two-dimensional plane.

Find the minimum radius of a circle such that all the points are inside or on it.

Constraints

* 2 \leq N \leq 50
* 0 \leq x_i \leq 1000
* 0 \leq y_i \leq 1000
* The given N points are all different.
* The values in input are all integers.

Input

Input is given from Standard Input in the following format:


N
x_1 y_1
:
x_N y_N


Output

Print the minimum radius of a circle such that all the N points are inside or on it.

Your output will be considered correct if the absolute or relative error from our answer is at most 10^{-6}.

Examples

Input

2
0 0
1 0


Output

0.500000000000000000


Input

3
0 0
0 1
1 0


Output

0.707106781186497524


Input

10
10 9
5 9
2 0
0 0
2 7
3 3
2 5
10 0
3 7
1 9


Output

6.726812023536805158

Solution (in PYTHON3):

Solution:
#!/usr/bin/env python3

import sys
import math
from bisect import bisect_right as br
from bisect import bisect_left as bl
sys.setrecursionlimit(2147483647)
from heapq import heappush, heappop,heappushpop
from collections import defaultdict
from itertools import accumulate
from collections import Counter
from collections import deque
from operator import itemgetter
from itertools import permutations
mod = 10**9 + 7
inf = float('inf')
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))

"""
[最小包含円]
中心座標(x,y)をx座標,y座標それぞれについて三分探索.
"""
n = I()
xy = [LI() for _ in range(n)]

def d(x1,y1,x2,y2):
    return math.sqrt((x1-x2)**2 + (y1-y2)**2)

def f(x,y):
    res = 0
    for x1,y1 in xy:
        res = max(res,d(x,y,x1,y1))
    return res

def g(x):
    l,r = 0,1000
    for _ in range(80):
        a = (l*2+r)/3
        b = (l+r*2)/3
        if f(x,a) > f(x,b):
            l = a
        else:
            r = b
    return f(x,l)

l,r = 0,1000
for _ in range(80):
    a = (l*2+r)/3
    b = (l+r*2)/3
    if g(a) > g(b):
        l = a
    else:
        r = b
print(g(l))