Always Cluttering Movers
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The Always Cluttering Movers (ACM) have several identical trucks.
Whenever they load up their trucks, they usually poorly distribute
the identical boxes.  Although they know how many boxes they want
in each truck, they usually do not manage to accomplish that because
of all their clutter.  Here is where you come in.  Given an initial
distribution of the boxes over the trucks and a desired final
distribution of the boxes over those trucks, you are asked to compute
how many boxes need to be moved.

Let's consider an example.  Assume that three trucks are used for 
a particular job.  Let the boxes are such that at most two boxes
fit in each truck.  Also assume that each truck contains one box
initially.  The desired distribution is: two boxes in the first
truck, no boxes in the second truck (so that the driver can visit
her mother for her birthday) and one box in the third truck.  Moving
the box from the second truck to the first truck will accomplish
this.

Input
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The input consists of multiple test cases.  Each test case starts
three positives integers, the number of boxes in total B (1 <= B <= 30), 
the maximal number of boxes that fit in one truck M (1 <= M <= 4), 
and the number of trucks T (1 <= T <= 10).  Each of next T lines 
contains the number of boxes in each truck.  This represents the 
initial distribution.  Next, another T lines are given, and this 
indicates the desired final distribution.  You may assume that 
the input is always valid.  The input is ended by three zeroes.

Output
------
For each test case, the output consists of a single integer, namely
the minimal number of boxes that need to be moved from one truck to 
another to morph the initial distribution into the final one.

Sample input
------------
3 2 3
1
1
1
2
0
1
0 0 0

Sample output
-------------
1