from collections import defaultdict,deque
class UnionFind:
    def __init__(self,N,label=None,f=None,weighted=False,rollback=False):
        self.N=N
        self.parents=[None]*self.N
        self.size=[1]*self.N
        self.roots={i for i in range(self.N)}
        self.label=label
        if self.label!=None:
            self.label=[x for x in label]
        self.f=f
        self.weighted=weighted
        if self.weighted:
            self.weight=[0]*self.N
        self.rollback=rollback
        if self.rollback:
            self.operate_list=[]
            self.operate_set=[]

    def Find(self,x):
        stack=[]
        while self.parents[x]!=None:
            stack.append(x)
            x=self.parents[x]
        if not self.rollback:
            if self.weighted:
                w=0
                for y in stack[::-1]:
                    self.parents[y]=x
                    w+=self.weight[y]
                    self.weight[y]=w
            else:
                for y in stack[::-1]:
                    self.parents[y]=x
        return x

    def Union(self,x,y,w=None):
        root_x=self.Find(x)
        root_y=self.Find(y)
        if self.rollback:
            self.operate_list.append([])
            self.operate_set.append([])
        if root_x==root_y:
            if self.weighted:
                if self.weight[y]-self.weight[x]==w:
                    return True
                else:
                    return False
        else:
            if self.size[root_x]<self.size[root_y]:
                x,y=y,x
                root_x,root_y=root_y,root_x
                if self.weighted:
                    w=-w
            if self.rollback:
                self.operate_list[-1].append((self.parents,root_y,self.parents[root_y]))
                self.operate_list[-1].append((self.size,root_x,self.size[root_x]))
                self.operate_set[-1].append(root_y)
                if self.label!=None:
                    self.operate_list[-1]((self.label,root_x,self.label[root_x]))
                if self.weighted:
                    self.operate_list[-1].append((self.weight,root_y,self.weight[root_y]))
            self.parents[root_y]=root_x
            self.size[root_x]+=self.size[root_y]
            self.roots.remove(root_y)
            if self.label!=None:
                self.label[root_x]=self.f(self.label[root_x],self.label[root_y])
            if self.weighted:
                self.weight[root_y]=w+self.weight[x]-self.weight[y]

    def Size(self,x):
        return self.size[self.Find(x)]

    def Same(self,x,y):
        return self.Find(x)==self.Find(y)

    def Label(self,x):
        return self.label[self.Find(x)]

    def Weight(self,x,y):
        root_x=self.Find(x)
        root_y=self.Find(y)
        if root_x!=root_y:
            return None
        return self.weight[y]-self.weight[x]

    def Roots(self):
        return list(self.roots)

    def Linked_Components_Count(self):
        return len(self.roots)

    def Linked_Components(self):
        linked_components=defaultdict(list)
        for x in range(self.N):
            linked_components[self.Find(x)].append(x)
        return linked_components
    
    def Rollback(self):
        assert self.rollback
        if self.operate_list:
            for lst,x,v in self.operate_list.pop():
                lst[x]=v
            for x in self.operate_set.pop():
                self.roots.add(x)            
            return True
        else:
            return False

    def __str__(self):
        linked_components=defaultdict(list)
        for x in range(self.N):
            linked_components[self.Find(x)].append(x)
        return "\n".join(f"{r}: {linked_components[r]}" for r in sorted(list(linked_components.keys())))


def dist2(x1, y1, x2, y2):
    return (x1-x2)**2 + (y1-y2)**2


def convex(Vs):
    """
    :param Vs(sorted by x): [[x1, y1], ... [xn, yn]]
    :return: upper, lower
    """
    def cross(x1, y1, x2, y2):
        return x1 * y2 - y1 * x2

    def is_ccw(x1, y1, x2, y2):
        return cross(x1, y1, x2, y2) > 0

    N = len(Vs)

    upper = deque()
    upper.append(Vs[0])
    upper.append(Vs[1])

    for i in range(2, N):
        V3 = Vs[i]
        x3, y3 = V3

        while len(upper) >= 2:
            V2 = upper.pop()
            V1 = upper.pop()
            x2, y2 = V2
            x1, y1 = V1

            upper.append(V1)

            if not is_ccw(x2-x1, y2-y1, x3-x2, y3-y2):
                upper.append(V2)
                upper.append(V3)
                break

        if len(upper) < 2:
            upper.append(V3)


    lower = deque()
    lower.append(Vs[-1])
    lower.append(Vs[-2])

    for i in range(N-3, -1, -1):
        V3 = Vs[i]
        x3, y3 = V3

        while len(lower) >= 2:
            V2 = lower.pop()
            V1 = lower.pop()
            x2, y2 = V2
            x1, y1 = V1

            lower.append(V1)

            if not is_ccw(x2-x1, y2-y1, x3-x2, y3-y2):
                lower.append(V2)
                lower.append(V3)
                break

        if len(lower) < 2:
            lower.append(V3)

    return upper, lower


def ConvexHull(xy):
    def NG(x, y):
        x0, y0 = res[-2]
        x1, y1 = res[-1]
        return (x-x0)*(y1-y0)-(x1-x0)*(y-y0) >= 0

    res = []
    xy.sort()
    for x, y in xy:
        while len(res) > 1 and NG(x, y): res.pop()
        res.append((x, y))
    under_n = len(res)
    for x, y in xy[-2::-1]:
        while len(res) > under_n and NG(x, y): res.pop()
        res.append((x, y))
    return res[:-1]

def RotatingCalipers(xy):
    def dist(i, j):
        ix, iy = xy[i]
        jx, jy = xy[j]
        return (ix-jx)**2+(iy-jy)**2

    def vec(i):
        x0, y0 = xy[i]
        x1, y1 = xy[(i+1)%n]
        return x1-x0, y1-y0

    def outer(i, j):
        vix, viy = vec(i)
        vjx, vjy = vec(j)
        return vix*vjy-viy*vjx

    n = len(xy)
    if n < 2: return 0
    if n == 2: return dist(0, 1)**0.5
    res = 0
    i = xy.index(min(xy))
    j = xy.index(max(xy))
    si, sj = i, j
    while i != sj or j != si:
        res = max(res, dist(i, j))
        if outer(i, j) > 0: j = (j+1)%n
        else: i = (i+1)%n
    return res**0.5

N=int(input())
D=2001
XY=[[] for d in range(D*D)]
X,Y=[],[]
for n in range(N):
    x,y=map(int,input().split())
    XY[(x//10+1000)*D+(y//10+1000)].append((x,y,n))
    X.append(x)
    Y.append(y)
UF=UnionFind(N)
for i in range(D):
    for j in range(D):
        if not XY[i*D+j]:
            continue
        for di in range(-1,2):
            for dj in range(-1,2):
                if (i+di)*D+(j+dj)>=D*D or not XY[(i+di)*D+(j+dj)]:
                    continue
                for x,y,n in XY[i*D+j]:
                    for xx,yy,nn in XY[(i+di)*D+(j+dj)]:
                        if (x-xx)**2+(y-yy)**2<=100:
                            UF.Union(n,nn)
ans=1
for lst in UF.Linked_Components().values():
    d = RotatingCalipers(ConvexHull([(X[i],Y[i]) for i in lst]))
    ans=max(ans,d+2)
print(ans)