whywhywhywhy??????
i can't find any mistake!!!
(my English is very bad,sorry)

 var i,j,n,hoh,ha,hb:longint;
     a:array[0..21]of longint;
procedure hh(x,y:integer);
 begin
  if y=1 then inc(ha,a[x]) else inc(hb,a[x]);
  if x<=n then
   begin
    if x<n then hh(x+1,1) else if abs(ha-hb)<hoh then hoh:=abs(ha-hb);
    if x<n then hh(x+1,0) else if abs(ha-hb)<hoh then hoh:=abs(ha-hb);
   end;
 end;
begin
 readln(n);
 hoh:=maxlongint;
 for i:=1 to n do read(a[i]);
 ha:=0; hb:=0;
 hh(1,1);
 ha:=0; hb:=0;
 hh(1,0);
 writeln(hoh);
end.