18  ENERGY = -4.7  reverse
    1 C       0    2   15    1
    2 C       1    3   14    2
    3 G       2    4   13    3
    4 C       3    5   12    4
    5 T       4    6   11    5
    6 C       5    7    0    6
    7 C       6    8    0    7
    8 T       7    9    0    8
    9 G       8   10    0    9
   10 T       9   11    0   10
   11 A      10   12    5   11
   12 G      11   13    4   12
   13 C      12   14    3   13
   14 G      13   15    2   14
   15 G      14   16    1   15
   16 C      15   17    0   16
   17 T      16   18    0   17
   18 G      17    0    0   18