Challenge

1-2

1-4

1-7

1-10

1-15

2-3

2-6

2-14

2-15

2-18

3-3

3-4

3-5

3-9

3-10

3-11

3-16

3-18

4-1

4-3

4-6

4-8

4-9

4-15

5-4