import sys,bisect,string,math,time,functools,random,fractions
from heapq import heappush,heappop,heapify
from collections import deque,defaultdict,Counter
from itertools import permutations,combinations,groupby
rep=range;R=range
def Golf():n,*t=map(int,open(0).read().split())
def I():return int(input())
def S_():return input()
def IS():return input().split()
def LS():return [i for i in input().split()]
def MI():return map(int,input().split())
def LI():return [int(i) for i in input().split()]
def LI_():return [int(i)-1 for i in input().split()]
def NI(n):return [int(input()) for i in range(n)]
def NI_(n):return [int(input())-1 for i in range(n)]
def StoLI():return [ord(i)-97 for i in input()]
def ItoS(n):return chr(n+97)
def LtoS(ls):return ''.join([chr(i+97) for i in ls])
def RA():return map(int,open(0).read().split())
def GI(V,E,ls=None,Directed=False,index=1):
    org_inp=[];g=[[] for i in range(V)]
    FromStdin=True if ls==None else False
    for i in range(E):
        if FromStdin:
            inp=LI()
            org_inp.append(inp)
        else:
            inp=ls[i]
        if len(inp)==2:
            a,b=inp;c=1
        else:
            a,b,c=inp
        if index==1:a-=1;b-=1
        aa=(a,c);bb=(b,c);g[a].append(bb)
        if not Directed:g[b].append(aa)
    return g,org_inp
def GGI(h,w,search=None,replacement_of_found='.',mp_def={'#':1,'.':0},boundary=1):
    #h,w,g,sg=GGI(h,w,search=['S','G'],replacement_of_found='.',mp_def={'#':1,'.':0},boundary=1) # sample usage
    mp=[boundary]*(w+2);found={}
    for i in R(h):
        s=input()
        for char in search:
            if char in s:
                found[char]=((i+1)*(w+2)+s.index(char)+1)
                mp_def[char]=mp_def[replacement_of_found]
        mp+=[boundary]+[mp_def[j] for j in s]+[boundary]
    mp+=[boundary]*(w+2)
    return h+2,w+2,mp,found
def TI(n):return GI(n,n-1)
def accum(ls):
    rt=[0]
    for i in ls:rt+=[rt[-1]+i]
    return rt
def bit_combination(n,base=2):
    rt=[]
    for tb in R(base**n):s=[tb//(base**bt)%base for bt in R(n)];rt+=[s]
    return rt
def gcd(x,y):
    if y==0:return x
    if x%y==0:return y
    while x%y!=0:x,y=y,x%y
    return y
def YN(x):print(['NO','YES'][x])
def Yn(x):print(['No','Yes'][x])
def show(*inp,end='\n'):
    if show_flg:print(*inp,end=end)

mo=10**9+7
inf=float('inf')
FourNb=[(-1,0),(1,0),(0,1),(0,-1)];EightNb=[(-1,0),(1,0),(0,1),(0,-1),(1,1),(-1,-1),(1,-1),(-1,1)];compas=dict(zip('WENS',FourNb));cursol=dict(zip('LRUD',FourNb))
l_alp=string.ascii_lowercase
#sys.setrecursionlimit(10**7)
read=sys.stdin.buffer.read;readline=sys.stdin.buffer.readline;input=lambda:sys.stdin.readline().rstrip()

show_flg=False
show_flg=True

ans=0


def check(x,y,r):
    for s,t in c:
        if (x-s)**2+(y-t)**2>r+1e-6:
            return False
    return True
    
 
def center_of_3points(x1,y1,x2,y2,x3,y3):
    cx = ((y1-y3)*(y1**2 -y2**2 +x1**2 -x2**2) -(y1-y2)*(y1**2 -y3**2 +x1**2 -x3**2)) / (2*(y1-y3)*(x1-x2)-2*(y1-y2)*(x1-x3))
    cy = ((x1-x3)*(x1**2 -x2**2 +y1**2 -y2**2) -(x1-x2)*(x1**2 -x3**2 +y1**2 -y3**2)) / (2*(x1-x3)*(y1-y2)-2*(x1-x2)*(y1-y3))
    r=((x1-cx)**2+(y1-cy)**2)
    return cx,cy,r
 
def rotate2D(x,y,q):
    s=x*math.cos(q)-y*math.sin(q)
    t=x*math.sin(q)+y*math.cos(q)
    return (s,t)


def cir2(x1,y1,x2,y2):
    p,q=(x1+x2)/2,(y1+y2)/2
    r=((x1-p)**2+(y1-q)**2)
    return p,q,r
 
ans=inf
 
n=I()
c=[]
CC=[]
rx=random.randint(1,10**3)
ry=random.randint(1,10**3)
for i in range(n):
    x,y=LI()
    x+=rx
    y+=ry
    CC.append((x,y))
 
 
def solve():
    ans=inf
    for i in range(n):
        x,y=CC[i]
        c.append((x,y))
    
    for i in range(n):
        for j in range(i+1,n):
                po=c[i]+c[j]
                x1,y1,x2,y2=po
                p,q,r=cir2(x1,y1,x2,y2)
                
                if check(p,q,r):
                    ans=min(ans,r)
    
    for i in range(n):
        for j in range(i+1,n):
            for k in range(j+1,n):
                x1,y1,x2,y2,x3,y3=CC[i]+CC[j]+CC[k]
                a,b= (x2-x1),(y2-y1)
                C,D= (x3-x1),(y3-y1)
                if a*D==b*C:
                    continue
                x1,y1,x2,y2,x3,y3=c[i]+c[j]+c[k]
                p,q,r=center_of_3points(x1,y1,x2,y2,x3,y3)
                
                if check(p,q,r):
                    ans=min(ans,r)

    return ans

print(solve()**0.5)


Measured memory_bytes: 85048