here is my code. In my computer he got AC on test#1. But in timus that got WA#1

var
 a:array[0..500010] of longint;

procedure sort(l,r:longint);
var
 i,j,p,x:longint;
begin randomize;
 i:=l; j:=r; x:=a[random(r-l+1)+l];
 repeat
  while x>a[i] do inc(i);
  while x<a[j] do dec(j);
  if i<=j then
   begin
    p:=a[i];a[i]:=a[j];a[j]:=p;
    inc(i); dec(j);
   end;
 until i>j;
 if i<r then sort(i,r);
 if l<j then sort(l,j);
end;

var
 p,j,k,n,i,temp,have:longint;
begin
 readln(n);
 for i:=1 to n do
  readln(a[i]);
 sort(1,n);
 temp:=-1;
 for i:=1 to n do
  begin
   if a[i]=temp then begin inc(have); continue; end;
   if n mod 2=1 then k:=1 else k:=0;
   if have>=n div 2+k then begin writeln(temp); halt; end;
   have:=1;temp:=a[i];
  end;
 if n=1 then writeln(temp);
end.