a b c d e f g h i j k l m n o p q r s t u v w x y z
bvrf
Because of the "a"....shift the b back one letter = a
Because of the d, shift the v back 4 letters = r
Because of the e, shift the r back 5 letters = m
Because of the g, shift the f back 7 letters = y
" a r m y "