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
0 2
1 5
1 3
0 11
 got on 
0 0
0 0
 in bus
1 5
1 11
 altogether
11


Solution

 
A
B
C
D
E
 got off 
0 0
0 2
1 5
1 3
0 11
 got on 
1 5
0 8
1 8
0 0
0 0
 in bus
1 5
1 11
1 14
0 11
 altogether
6
12
15
11


Solve exercises