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 Python (3.4.3) (judge verdict: Wrong Answer)

n = int(input())
s = [input() for _ in range(n)]

tail_a_num = 0
head_b_num = 0
both_num = 0
cnt = 0
for i in s:
  if i[0] == 'B':
    head_b_num += 1
  if i[-1] == 'A':
    tail_a_num += 1
  if i[0] == 'B' and i[-1] == 'A':
    both_num += 1
  if i != 'AB':
  	cnt += i.count('AB')

cnt += both_num - 1
head_b_num -= both_num
tail_a_num -= both_num
if head_b_num > 0:
  cnt += 1
  head_b_num -= 1
if tail_a_num > 0:
  cnt += 1
  tail_a_num -= 1

cnt += min(head_b_num,tail_a_num)
  
print(cnt)