program ppg(input,output);
var
 n:longint;
 now,max1:longint;
 i,j,k:longint;
 a:array[1..50,1..2]of longint;
 way:array[1..50,1..50]of longint;

procedure fuck(x,y:longint);
begin
 now:=0;
 now:=abs(a[x,1]-a[y,1])+abs(a[x,2]-a[y,2]);
 if now mod 2=0 then now:=now div 2
  else now:=(now div 2)+1;
 way[x,y]:=now;
 way[y,x]:=now;
end;

function max(a,b:longint):longint;
begin
 if a>b then max:=a else max:=b;
end;

begin
 assign(input,'ppg.in');
 reset(input);
 readln(n);
 for i:=1 to n do readln(a[i,1],a[i,2]);
 close(input);

 for i:=1 to n do
  for j:=i+1 to n do fuck(i,j);

 for k:=1 to n do
  for i:=1 to n do
   for j:=1 to n do
    if max(way[i,k],way[k,j])<way[i,j] then
     way[i,j]:=max(way[i,k],way[k,j]);

 for i:=1 to n do
  for j:=1 to n do
   if way[i,j]>max1 then max1:=way[i,j];

 assign(output,'ppg.out');
 rewrite(output);
 writeln(max1);
 close(output);
end.