m
i
The letter "A" or "a" precedes the letter "B" or "b".
The next letter is U A -> miss a letter (B) -> C C -> miss two letters (DE) -> F F -> miss three letters (GHI) -> J J -> miss four letters (KLMN) -> O and so on....
K
S
B
Check out the link for the sequence.
the next letter would be 'b'
f
B
i
c
I,V
CRC CBO and COL
bala
d
b