Strimko (7)

  1 b―b c 5 c
   ×  |  × × 
  b 2 b 4 c a
     × / / \ 
  d b 3 c e c
   ×     / × 
  b d 6 e c e
    | |    / 
  d d f―f e f
  | |    ×  |
  d―d e―e f―f