Task prave

Task Prave
I have a problem in the following code

program prave;
 var i,x,n,y,max : longint;
       zbirx,zbiry : array[-32000..32000] of int64;
           begin
           max:=0;
           readln(n);
   for i:=1 to n do begin
   readln(x,y);
  zbirx[x]:=zbirx[x]+1;
  zbiry[y]:=zbiry[y]+1;
     if zbirx[x]>max then max:=zbirx[x];
     if zbiry[y]>max then max:=zbiry[y]; 
   end;
writeln(max);
end.

Any help???