2 18 12 8 14 20 6 4 10 16
7
x
2
=
4
x
2
=
9
x
2
=
6
x
2
=
3
x
2
=
8
x
2
=
10
x
2
=
1
x
2
=
2
x
2
=
5
x
2
=
0
x
2
=
0