Which of the following is a sentence of Truth functional logic strictly speaking $[$i$.$e$.$ not allowing for relaxed bracketing conventions$]$:

$1.($A$)$

$2.$ P $$ Q

$3.$S

$4.(53)$

$5.$P

$6.($M $$ F$)$

$7.($A $->($A $$F$))($D $$ E$)$

$8.(($F $$D $->$ J$)($C $$ D$))$

$9.(($Z $$ S $)->$ W$)($J $$ X$)$