const t=600;
      n=30000;
var a:array[1..30000]of word;
    time,point,address:word;ch:char;
begin
     assign(input,'1.in');
     reset(input);
     assign(output,'1.out');
     rewrite(output);
     fillchar(a,sizeof(a),0);
     while not eof do begin
           read(time);read(ch);read(ch);
           if ch='+' then
              begin
              point:=0;
              repeat
                    inc(point);
                    if (a[point]<=time) then break;
                    until false;
                    a[point]:=time+600;
                    writeln(point);
              end;
           if ch='.' then
              begin
                   read(address);
                   if a[address]<=time then writeln('-')
                                       else begin
                                            writeln('+');
                                            a[address]:=time+600;
                                            end;
              end;
     end;
     close(input);close(output);
end.