program C0486;
 var CO,CX,MO,MX,ans:longint;
 begin
  assign(input,'bs.in');
  reset(input);
  assign(output,'bs.out');
  rewrite(output);

  while not eof do begin
   readln(CO,CX,MO,MX);
   ans:=0;

   if MO*MX<>0 then begin
    inc(ans,MO+MX);
    dec(CO,MO);
    dec(CX,MX);
    if CO=CX then inc(ans,CO+CX)
     else
      if CO>CX then inc(ans,CX+CX+1) else inc(ans,CO+CO+1 );
   end;
   if ans<0 then writeln(0) else writeln(ans);
  end;

  close(input);
  close(output);
 end.