大模拟。

program Algebra;

type
  TItem=record k:longint;p:string[10]; end;
  TAlg=array[1..50]of TItem;

var
  s1,s2:string;
  p1,p2,l1,l2,n1,n2,m:integer;
  t,t1,t2:TAlg;

function GetItem(var s:string;var ps,len:integer):TItem;
  var
    st,st1:string;
    it:TItem;
    o,code:integer;
  begin
    st:=s[ps];
    inc(ps);
    while (ps<=len)and(s[ps]<>'+')and(s[ps]<>'-') do
    begin
      st:=st+s[ps];
      inc(ps);
    end;

    o:=pos('x',st);
    if o=0
      then begin
        val(st,it.k,code);
        it.p:='';
        exit(it);
      end;
    if o=2
      then begin if st[1]='+' then it.k:=1 else it.k:=-1; end
      else begin
        st1:=copy(st,1,o-1);
        val(st1,it.k,code);
      end;
    it.p:=copy(st,o,255);
    exit(it);
  end;

function cmp(a,b:string):boolean;
  begin
    if length(a)>length(b) then exit(true);
    if length(a)<length(b) then exit(false);
    exit(a>b);
  end;

procedure solve;
  var
    ex:TItem;
    i,j:integer;
  begin
    //init
    p1:=1;l1:=length(s1);
    p2:=1;l2:=length(s2);
    n1:=0;n2:=0;
    while p1<=l1 do begin inc(n1); t1[n1]:=GetItem(s1,p1,l1); end;
    while p2<=l2 do begin inc(n2); t2[n2]:=GetItem(s2,p2,l2); end;
    //run
    m:=0;
    p1:=1;p2:=1;
    while (p1<=n1)and(p2<=n2) do
    begin
      inc(m);
      if t1[p1].p=t2[p2].p
        then begin
          t[m].p:=t1[p1].p;
          t[m].k:=t1[p1].k+t2[p2].k;
          inc(p1);inc(p2);
          continue;
        end;
      if cmp(t1[p1].p,t2[p2].p)
        then begin
          t[m]:=t1[p1];inc(p1);
        end
        else begin
          t[m]:=t2[p2];inc(p2);
        end;
    end;
    while p1<=n1 do begin
      inc(m);
      t[m]:=t1[p1];
      inc(p1);
    end;
    while p2<=n2 do begin
      inc(m);
      t[m]:=t2[p2];
      inc(p2);
    end;
  end;

procedure Print;
  var
    i:integer;
    flag:boolean;
  begin
    flag:=true;
    for i:=1 to m do
    begin
      if t[i].k=0 then continue;
      flag:=false;
      if (t[i].k>0)and(i>1)
        then write('+');
      if t[i].p=''
        then write(t[i].k)
        else
      if t[i].k=-1
        then write('-')
        else
      if t[i].k<>1 then write(t[i].k);
      write(t[i].p);
    end;
    if flag then write(0);
    writeln;
  end;

begin
  readln(s1);readln(s2);
  if (s1[1]<>'+')and(s1[1]<>'-') then s1:='+'+s1;
  if (s2[1]<>'+')and(s2[1]<>'-') then s2:='+'+s2;
  solve;
  Print;

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