$ python iou.py -new
You can type 'help' (without quotes) at any time for help.
> help
Accepted expressions:
    'help':  prints this help info
    'print':  prints out current debts
    'simplify':  simplifies current debts
    'add <new users separated by spaces>': adds users to system
    'clear':  clears all debts (with no warning). use with caution
    '<name> owes <name> <amount>'
    '<name> paid <amount> for <names separated by spaces>':  for splitting
    '<name> paid <amount> for all'
> add alice bob carol
> alice owes bob 5
> bob owes carol 5
> print
alice owes bob $5.00
bob owes carol $5.00
> simplify
> print
alice owes carol $5.00