For the manager of a theatre, setting the price of a ticket is a rather delicate
matter. Suppose that a theatre has n (<= 1000000) seats, and that if
you give away the tickets for free, all the seats will be taken. After some sort
of investigation, it is estimated that for every p yuans of increase of
the ticket price, the theatre will lose m audiences. But the audiences
will not leave until the ticket price jumps up a complete step of p yuans.
For example, if given p=1.00 and m=10, no audience will be lost
if the price is set to be 0.99 yuans, and 10 will be lost if the price is 1.99
yuans. It costs R yuans for the theatre to run each show, and S
yuans to serve each of the audiences during each show. Now your job is to write
a program to maximize the total revenue of each show for the theatre.