var
  ggg,s,s1,s2:string;
  i,p,itog1,itog2:integer;
  mass:array [1..5] of integer;
  a,b,e:integer;
begin
  e:=10;
  read(s);
  ggg:=copy(s,1,1);
  val(ggg,b,e);
  mass[1]:=b;
  p:=1;
    for i:=2 to length(s) do

      if i mod 2 <>0 then
        begin
    s1:=copy(s,i,1);
    val(s1,a,e);
    mass[i-p]:=a;
    p:=p*2;
    end
  else
    begin
    s2:=s2+copy(s,i,1);
    end;


    if (s2[1]='+') then itog1:= mass[1]+mass[2]
    else itog1:= mass[1]-mass[2];

for i:=2 to length(s2) do
  begin
  if (s2[i]='+') then

    itog2:=itog1+mass[i+1]
    else
    itog2:=itog1-mass[i+1];
  end;
writeln(itog2);


end.