23 into 20 best min fragment found: 7
  Cut up 23 sticks of length 20 like this:
    5 x (10 + 10)
    4 x (9 + 11)
    4 x (8 + 12)
    10 x (7 + 13)
  Reassemble as 20 sticks of length 23 like this:
    4 x (11 + 12)
    10 x (10 + 13)
    2 x (7 + 8 + 8)
    4 x (7 + 7 + 9)