import sys
read=sys.stdin.buffer.read
readline=sys.stdin.buffer.readline
readlines=sys.stdin.buffer.readlines
class UnionFind:
    def __init__(self, n):
        self.n=n
        self.par=[-1]*n
    def find(self, x):
        if self.par[x]<0:
            return x
        self.par[x]=self.find(self.par[x])
        return self.par[x]
    def unite(self, x, y):
        x=self.find(x)
        y=self.find(y)
        if x==y:
            return False
        if self.par[x]<self.par[y]:
            x, y=y, x
        self.par[y]+=self.par[x]
        self.par[x]=y
        return True
    def same(self, x, y):
        return self.find(x)==self.find(y)
    def size(self, x):
        return -self.par[self.find(x)]

n=int(readline())
xy=list(map(int, read().split()))
x=xy[::2]
y=xy[1::2]
import itertools
es=[((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]), i, j) for i, j in itertools.combinations(range(n), 2)]
es.sort()
uf=UnionFind(n)
mn=0
for e in es:
    uf.unite(e[1], e[2])
    if uf.same(0, n-1):
        mn=e[0]
        break
l, r=0, 2*10**8
while r-l>1:
    m=(l+r)//2
    if 100*m*m>=mn:
        r=m
    else:
        l=m
print(10*r)