This one is too easy but included anyway for completeness (why not?)
Input Description
-----------------
The first line of input will be an integer N, which is for the number of rows
in each list. Each list has N-lines of two space-delimited strings: the first
string will be the unique item name (without spaces), the second string will be
the price (in whole-integer cents). The second list, following the same format,
will have the same unique item-names, but with the correct price. Note that the
lists may not be in the same order!
Output Description
------------------
For each item that has had its price changed, print a row with the item name
and the price difference (in cents). Print the sign of the change (e.g. '+' for
a growth in price, or '-' for a loss in price). Order does not matter for
output.
{% gist 8498879 %}