Jigsaw puzzle challenge example

1 a
B

B 4
  c

  D
A 4 e
  c

  D
A 4 e

  c
c 3 a
  d

b
3 a

  C
E 5 b

B 3 b
  d

  C
E 5
  a

b
2 C
B

A 2 b
  C

  A
B 6