program pp3(input,output);
var
ans,t:int64; i,n,j:integer;
data:array[1..50,1..2] of longint;
function max(a,b:int64):int64 ;
 begin
 if a>b then max:=a else max:=b;
 end;
begin
assign(input,'ppg.in');
assign(output,'ppg.out');
reset(input);
rewrite(output);
readln(n);
for i:= 1 to n do
readln(data[i,1],data[i,2]);
close(input);
ans:=0;
 if n=1 then begin  writeln(0); close(output);halt;  end;
 for i:= 1 to n do
  for j:= i+1 to n do
   begin

     t:=max(abs(data[i,1]-data[j,1]),abs(data[i,2]-data[j,2]));
     ans:=max(ans,t);
   end;
   writeln(ans);
   close(output) ;
 end.