A
  B
    E
    F
      H
      I
      J
  C
    G
    K
      L
    M
  D
    N
Préfixe : A B E F H I J C G K L M D N 
Postfixe : E H I J F B G L K M C N D A 
E and G are cousins: true
B and D are cousins: false
L and N are cousins: false