program ex;
var
a:array[1..1000000] of longint;
z,xj,xc,n,i,r,l:longint;
c:real;

procedure init;
begin
  assign(input,'groupa.in');
  assign(output,'groupa.out');
  reset(input);
  rewrite(output);
  readln(n);
  z:=0;
  for i:=1 to n do begin read(a[i]);z:=z+a[i];end;
  readln(l,r);
  close(input);
  xj:=0;
  xc:=0;
end;

begin
  init;
  c:=z/n;
  if (c>=l) and (c<=r) then
  begin
    for i:=1 to n do
    begin
      if a[i]>r then xc:=xc+(a[i]-r);
      if a[i]<l then xj:=xj+(l-a[i]);
    end;
  end
  else begin writeln('-1');close(output);halt;end;
  if (xc>=xj) then writeln(xc) else writeln(xj);
  close(output);
end.