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
s_array = n.times.map{gets.chomp}
first_b = 0
last_a = 0
both = 0
cnt = 0
s_array.each do|s|
  (0..s.size-2).each do|i|
    if s.slice(i,2) == "AB"
      cnt += 1
    end
  end
  if s[0] == "B" && s[-1] == "A"
    both += 1
  elsif s[0] == "B"
    first_b += 1
  elsif s[-1] == "A"
    last_a += 1
  end
end

if both != 0
  cnt += both - 1
  both = 1
end

cnt += [[first_b,last_a + both].min,[first_b + both,last_a].min].max

puts cnt