19  1
    1 G       0    2    0    1
    2 T       1    3    0    2
    3 C       2    4   19    3
    4 C       3    5   18    4
    5 T       4    6   17    5
    6 C       5    7    0    6
    7 T       6    8    0    7
    8 T       7    9    0    8
    9 C       8   10    0    9
   10 T       9   11    0   10
   11 C      10   12    0   11
   12 G      11   13    0   12
   13 A      12   14    0   13
   14 T      13   15    0   14
   15 C      14   16    0   15
   16 C      15   17    0   16
   17 A      16   18    5   17
   18 G      17   19    4   18
   19 G      18    0    3   19