program ubstst;

{$I ubsmod.typ}

var i,r : ubselement;
    u : ubslink;
    op : char;

{$I ubsmod.ext}

begin
while 5 < 10 do
   begin
   write ('m,i,s,d....');
   readln (op);
   case op of
	'm' : ubsmakenull(u);
        'i' : begin
                 write('character... ');
                 readln (i);
                 ubsinsert(i,u);
              end;
        's' : begin
                 write('character... ');
                 readln (i);
                 if ubssearch(i,r,u) then writeln(r) else writeln ('not');
              end;
       'd': ubsdump(u,output);
        end;
   end;
end.

.