21 into 19 best min fragment found: 13/2
  Cut up 21 sticks of length 19 like this:
    3 x (9 + 10)
    6 x (17/2 + 21/2)
    3 x (8 + 11)
    3 x (7 + 12)
    6 x (13/2 + 25/2)
  Reassemble as 19 sticks of length 21 like this:
    3 x (21/2 + 21/2)
    3 x (10 + 11)
    3 x (9 + 12)
    6 x (17/2 + 25/2)
    1 x (7 + 7 + 7)
    3 x (13/2 + 13/2 + 8)