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: Accepted)

both = []
left = []
right = []
ans = 0

n = gets.to_i
n.times do
  s = gets.chomp
  ans += s.scan(/AB/).length
  if s[0] == "B" and s[-1] == "A"
    both << s
  elsif s[0] == "B"
    left << s
  elsif s[-1] == "A"
    right << s
  end
end

if both.length > 0
  ans += both.length - 1
  if left.length > 0
    left.pop
    ans += 1
  end
  if right.length > 0
    right.pop
    ans += 1
  end
end

while left.length > 0 and right.length > 0
  left.pop
  right.pop
  ans+= 1
end

puts ans