use strict;
my @F = (
      1,
      2,
      4,
      8,
      32..64,
      26
     );

sub range{
  my($lo, $hi) = @_;
  return grep {$F[$_] >= $lo and $F[$_] <= $hi} 0..$#F;
}
print join(',', range(25,35)), "\n";