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