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 Ruby (2.3.3) (judge verdict: Wrong Answer)

n = gets.to_i
strs = []
cnt = 0
n.times do |i|
  str = gets.gsub(/\n/,"").downcase
  strs << str
  cnt += str.scan("ab").count
end
a_b_cnt = 0
strs.each_with_index do |elm, i|
  if elm.match(/^b.*a$/)
    a_b_cnt+=1 
    strs.delete_at(i)
  end
end
a_last_cnt = strs.select{|s| s.match(/a$/)}.count
b_first_cnt = strs.select{|s| s.match(/^b/)}.count
 
cnt += ((a_b_cnt <= 1)? 0 : (a_b_cnt - 1))
 
if a_b_cnt > 0 
  if a_last_cnt <= b_first_cnt
    a_last_cnt += 1
  else
    b_first_cnt += 1
  end
end
 
cnt += (a_last_cnt <= b_first_cnt)?a_last_cnt:b_first_cnt
p cnt