import sys,math
input=lambda:sys.stdin.readline().rstrip()
class unionFind:
    def __init__(self,N):
        self.N=N
        self.parent=[-1 for i in range(N)]
        self.size=[1 for i in range(N)]
    def find(self,x):
        path=[x]
        while self.parent[path[-1]]!=-1:
            path.append(self.parent[path[-1]])
        for i in path[:-1]:
            self.parent[i]=path[-1]
        return path[-1]
    def unite(self,x,y):
        roots=sorted([self.find(x),self.find(y)],key=lambda _:self.parent[_])
        if roots[0]!=roots[1]:
            self.parent[roots[0]]=roots[1]
            self.size[roots[1]]+=self.size[roots[0]]
def d(A,i,j):
	return (A[i][0]-A[j][0])**2+(A[i][1]-A[j][1])**2
N=int(input())
if N==0:
	print(1)
	sys.exit()
A=[list(map(int,input().split())) for i in range(N)]
u=unionFind(N)
mem={}
ans=0
for i in range(N):
	for j in range(i):
		if d(A,i,j)<=100:
			u.unite(i,j)
for i in range(N):
	if not u.find(i) in mem:
		mem[u.find(i)]=[]
	for j in mem[u.find(i)]:
		ans=max(d(A,i,j),ans)
	mem[u.find(i)].append(i)
print(pow(ans,0.5)+2)