Structure statistics are often calculated only over the well-ordered region(s)
of the biopolymer. Portions of the macromolecule are often mobile and
disordered, hence they are excluded in calculating the statistics. To define
the range(s) over which the statistics are calculated, enter the beginning
residue number(s): e.g. if the regions used were 5-32 and 41-69, enter 5,41