The next letter in the sequence AFAHMAS is "A." The pattern alternates between the letter "A" and the first letters of the words in the phrase "For Every letter" (F, H, M, S). Therefore, after "S," the sequence returns to "A."
I is the next letter.
a
A
The next letter is U.
s
In the alphabet the letter that comes after Q is the letter R. The letter that comes before Q would be P.
A
HS
The next letter is U.
l
p
It is: Y