15 into 7 best min fragment found: 3
  Cut up 15 sticks of length 7 like this:
    15 x (3 + 4)
  Reassemble as 7 sticks of length 15 like this:
    5 x (3 + 4 + 4 + 4)
    2 x (3 + 3 + 3 + 3 + 3)