var
  ncb:array[1..30000]of boolean;
  nct:array[1..30000]of longint;
  i,j,k,n,t:longint;
  c:char;
begin
  repeat
    read(t,c);read(c);
    if c='.'
    then begin
           readln(n);
           if ncb[n]
           then begin
                  if t-nct[n]<600
                  then begin
                         writeln('+');
                         nct[n]:=t;
                       end
                  else writeln('-');
                end
           else writeln('-');
         end
    else begin
           i:=1;
           while (t-nct[i]<600) and (ncb[i]=true) do inc(i);
           ncb[i]:=true;
           nct[i]:=t;
           writeln(i);
         end;
  until eof;
end.

there is 30001 number of box in this case...