\BOOKMARK [1][-]{section.1}{Introduction}{}% 1
\BOOKMARK [1][-]{section.2}{Proofs of Theorems 1\2054}{}% 2
\BOOKMARK [2][-]{subsection.2.1}{The case mod 5}{section.2}% 3
\BOOKMARK [2][-]{subsection.2.2}{The cases mod 25}{section.2}% 4
\BOOKMARK [2][-]{subsection.2.3}{The cases mod 7}{section.2}% 5
\BOOKMARK [2][-]{subsection.2.4}{The case mod 49}{section.2}% 6
\BOOKMARK [1][-]{section.3}{Final remarks}{}% 7
\BOOKMARK [1][-]{section.4}{Acknowledgements}{}% 8