Problem:
Score : 400 points

Problem Statement

Snuke has N strings. The i-th string is s_i.

Let us concatenate these strings into one string after arranging them in some order.
Find the maximum possible number of occurrences of AB in the resulting string.

Constraints

1 \leq N \leq 10^{4}

2 \leq |s_i| \leq 10

s_i consists of uppercase English letters.

Input

Input is given from Standard Input in the following format:

N
s_1
\vdots
s_N

Output

Print the answer.

Sample Input 1

3
ABCA
XBAZ
BAD

Sample Output 1

2

For example, if we concatenate ABCA, BAD and XBAZ in this order, the resulting string ABCABADXBAZ has two occurrences of AB.

Sample Input 2

9
BEWPVCRWH
ZZNQYIJX
BAVREA
PA
HJMYITEOX
BCJHMRMNK
BP
QVFABZ
PRGKSPUNA

Sample Output 2

4

Sample Input 3

7
RABYBBE
JOZ
BMHQUVA
BPA
ISU
MCMABAOBHZ
SZMEHMA

Sample Output 3

4

Solution in Haskell (GHC 7.10.3) (judge verdict: Wrong Answer)

import Control.Monad

main=do
  n<-readLn
  ss<-replicateM n getLine
  print $ solve n ss

solve :: Int->[String]->Int
solve n ss
  | lA == lAfB && fB == lAfB = nAB + bonus - 1
  | otherwise = nAB + bonus
  where
  bonus = min lA fB
  count [] = 0
  count ('A':'B':s)=1+count s
  count (c:s)=count s
  nAB = sum$map count ss
  lAs = filter((=='A').last)ss
  lA = length lAs
  fB = length$filter((=='B').head)ss
  lAfB = length$filter((=='B').head)lAs