$p=*0...n=gets.to_i
a=$p.map{Complex(*gets.split)}
d=$p.map{|u|$p.map{|v|(a[u]-a[v]).abs}}
def r u;u==$p[u]?u:$p[u]=r($p[u])end
n.times{|u|n.times{|v|d[u][v]>10||$p[r v]=r(u)}}
z=1
n.times{|u|n.times{|v|r(u)==r(v)&&z=[z,2+d[u][v]].max}}
p z