number of vertices :  20 
number of required edges  16 
1 2 5 5 15
1 6 7 7 8
2 3 2 2 4
3 4 1 1 3
4 5 3 3 5
5 6 1 1 3
7 8 3 3 7
8 9 7 7 7
8 10 2 2 4
10 11 2 2 3
12 13 6 6 18
14 15 3 3 4
15 16 9 9 16
17 18 5 5 13
18 19 3 3 5
19 20 10 10 15
number of non required edges  19 
2 5 2 2 0
4 7 7 7 0
4 12 19 19 13
4 14 17 17 12
5 16 8 8 6
5 20 10 10 9
7 11 5 5 2
7 14 17 17 12
9 10 4 4 1
9 12 9 9 4
9 14 15 15 4
9 16 24 24 14
12 14 10 10 0
12 16 19 19 9
13 16 14 14 3
13 17 10 10 0
16 17 12 12 6
16 20 8 8 5
18 20 3 3 2
