2010007104

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Project ID: 
2010007104
Source Problem: 
Accepted: 
0
Clonable: 
1
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0
There are 5 different roads between cities A and B. Find the number of possible ways from the city A to the city B and back, if it is required to use one road from A to B and another different one from B to A.
54=20
5+4=9
55=25
25=10