13 into 12 best min fragment found: 4
  Cut up 13 sticks of length 12 like this:
    3 x (6 + 6)
    6 x (5 + 7)
    4 x (4 + 4 + 4)
  Reassemble as 12 sticks of length 13 like this:
    6 x (6 + 7)
    6 x (4 + 4 + 5)