The stores manager has sorted all kinds of goods in an alphabetical
order of their labels. All the kinds having labels starting with the
same letter are stored in the same warehouse (i.e. in the same
building) labelled with this letter. During the day the stores manager
receives and books the orders of goods which are to be delivered from
the store. Each order requires only one kind of goods. The stores
manager processes the requests in the order of their booking.
You know in advance all the orders which will have to be processed by
the stores manager today, but you do not know their booking
order. Compute all possible ways of the visits of warehouses for the
stores manager to settle all the demands piece after piece during the
Input file ORDERS.IN contains a single line with all labels of the
requested goods (in random order). Each kind of goods is represented
by the starting letter of its label. Only small letters of the English
alphabet are used. The number of orders doesn't exceed 200.
Output file ORDERS.OUT will contain all possible orderings in which
the stores manager may visit his warehouses. Every warehouse is
represented by a single small letter of the English alphabet -- the
starting letter of the label of the goods. Each ordering of warehouses
is written in the output file only once on a separate line and all the
lines containing orderings have to be sorted in an alphabetical order
(see the example). No output will exceed 2 megabytes.