Update BalanceWeight.java

There are some weighing scales which has left and right plates. The weighing scales are very compact and plates are pretty big. As a result of this, one weighing scale can be put into another weighing scale's plate. At the same time some weights can be put onto the plates along with the weighing scale. The empty weighing scale has a fixed predefined weight. Only one weighing scale can be accommodated in one plate. However any number of weights can be put into the plate, even after putting one weighing scale. One such arrangement is given as an input to your program. There are enough supply of weights and they can be of fractional value as well. The program should add weights to the plates to balance the weighing scales. The ultimate result would be that all the weighing scales are balanced.