class UnionFind:
    def __init__(self, n):
        self.n=n
        self.parent_size=[-1]*n
    def merge(self, a, b):
        x, y=self.leader(a), self.leader(b)
        if x == y: return 
        if abs(self.parent_size[x])<abs(self.parent_size[y]): x, y=y, x
        self.parent_size[x] += self.parent_size[y] 
        self.parent_size[y]=x
        return 
    def same(self, a, b):
        return self.leader(a) == self.leader(b)
    def leader(self, a):
        if self.parent_size[a]<0: return a
        self.parent_size[a]=self.leader(self.parent_size[a])
        return self.parent_size[a]
    def size(self, a):
        return abs(self.parent_size[self.leader(a)])
    def groups(self):
        result=[[] for _ in range(self.n)]
        for i in range(self.n):
            result[self.leader(i)].append(i)
        return [r for r in result if r != []]
def connect(d):
    uni=UnionFind(n)
    for i in range(n):
        for j in range(i+1,n):
            if g[i][j]<=d:
                uni.merge(i,j)
    return uni.same(0,n-1)
n=int(input())
p=[list(map(int,input().split())) for _ in range(n)]
g=[[0]*n for _ in range(n)]
for i in range(n):
    x,y=p[i]
    for j in range(i+1,n):
        X,Y=p[j]
        dx=x-X
        dy=y-Y
        g[i][j]=dx**2+dy**2
l=0
r=10**12
while r-l>1:
    mid=(r+l)//2
    if connect(mid**2*100):
        r=mid
    else:
        l=mid
print(r*10)