//int DegList[] = {8,7,7,6,6,6,4,3,2,1 };
//int DegList[] = {9,8,8,7,7,5,4,4,3,3 };
//int DegList[] = { 9,5,4,4,4,3,3,3,2,1 };
int DegList[] = { 9,7,6,6,5,5,3,3,2,2 };
//                0 6 5 5 4 4 2 2 1 1
//                0 0 5 5 3 3 1 1 0 0
//                0 0 0 4 2 2 0 0 0 0
//                0 0 0 2 1 1 0 0 0 0
//                0 0 0 2 0 0 0 0 0 0

9,7,6,6,5,5,3,3,2,2

9,7,6,6,5,5,3,3,2,2
9,8,7,6,5,4,3,2,1,0
0 6 5 5 4 4 2 2 1 1
x 8 7 6 5 4 3 2 1 0

0 0 5 5 3 3 1 1 0 0
x x 5 4 3 3 1 0 0 0 
0 0 0 4 2 2 0 0 0 0
0 0 0 2 1 1 0 0 0 0
0 0 0 2 0 0 0 0 0 0

0 0 5 4 3 3 1 1 0 1
x x 6 5 4 3 2 1 1 0 
0 0 0 3 2 2 0 0 0 1
0 0 0 0 1 1 0 0 0 0
0 0 0 0 0 0 0 0 0 0

The problem is reduction in the number of available vertices at the end.
The second match-up reduces the number of available vertices by two.
Any other match-up reduces the number of available vertices by one.
Once the last two vertices are consumed, failure is guaranteed at vertex 3.
