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)

import re

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

count_ab = 0
b_a = 0
__a = 0
b__ = 0

for si in ss:
  count_ab += len(re.findall('AB',si))
  if si[0]=='B' and si[-1]=='A':
    b_a += 1
  elif si[0]=='B':
    b__ += 1
  elif si[-1]=='A':
    __a += 1
  else:
    pass

count_ab += min(__a, b__)
if abs(__a - b__) > 0 and b_a > 0:
  count_ab +=1

if b_a > 0:  
  count_ab += b_a - 1

print(count_ab)