Teachers and parrents

Instructions:

The table describes the number of passengers entering and leaving at stations A, B, C ... Bus arrives without passengers at the first station. All passengers get off on the last station. We do keep rules of decency - first get off and then get in.

Example

 
A
B
C
D
E
 got off 
0 0
3 2
3 5
3 0
4 3
 got on 
4 2
0 0
 in bus
4 2
4 5
 altogether
7


Solution

 
A
B
C
D
E
 got off 
0 0
3 2
3 5
3 0
4 3
 got on 
4 2
3 5
2 1
4 2
0 0
 in bus
4 2
4 5
3 1
4 3
 altogether
6
9
4
7


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