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 PyPy3 (2.4.0) (judge verdict: Accepted)

n = int(input())
s = [input() for _ in range(n)]
ab = 0
ba = 0
last_a = 0
first_b = 0
for i in range(n):
  if s[i][0] == "B" and s[i][-1] == "A":
    ba += 1
  elif s[i][-1] == "A":
    last_a += 1
  elif s[i][0] == "B":
    first_b += 1
  ab += s[i].count("AB")
if last_a == 0 and first_b == 0:
  print(ab+ba-1) if ba != 0 else print(ab)
else:
  print(ab+ba+min(last_a,first_b))