# read more lines as needed
while (<IN>) {
  if (/_\[\d]([^_]*)_/) {
    push @titles, $1;
  }
  elsif (/_\[\d]([^_]*)/) {
    push @titles, $1;
    while (<IN>) {
      if (/([^_]*)/) { $titles[-1] .= $1 }
      last if /_/;
    }
  }
}