import sys

sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


class UnionFind:
    def __init__(self,n):
        self.par = [i for i in range(n+1)]  # 親のノード番号
        self.rank = [0]*(n+1)

    def find(self,x):  # xの根のノード番号
        if self.par[x] == x:
            return x
        else:
            self.par[x] = self.find(self.par[x])
            return self.par[x]

    def same_check(self,x,y):  # x,yが同じグループか否か
        return self.find(x) == self.find(y)

    def unite(self,x,y):  # x,yの属するグループの併合
        x = self.find(x)
        y = self.find(y)
        if self.rank[x] < self.rank[y]:
            x,y = y,x
        if self.rank[x] == self.rank[y]:
            self.rank[x] += 1
        self.par[y] = x


N = I()
XY = [(0,0)]+[tuple(MI()) for _ in range(N)]

dist = [[0]*(N+1) for _ in range(N+1)]
for i in range(1,N):
    x0,y0 = XY[i]
    for j in range(i+1,N+1):
        x1,y1 = XY[j]
        dist[i][j] = (x0-x1)**2+(y0-y1)**2


def f(z):
    UF = UnionFind(N)
    for i in range(1,N):
        for j in range(i+1,N+1):
            if dist[i][j] <= z**2:
                UF.unite(i,j)
    if UF.same_check(1,N):
        return True
    return False


ng = 0
ok = 2*10**8
while ng+1 < ok:
    mid = (ng+ok)//2
    if f(10*mid):
        ok = mid
    else:
        ng = mid

print(10*ok)