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 sys

input = sys.stdin.readline
n = int(input())
s_list = []
a_end_num = 0
b_start_num = 0
cnt = 0
for _ in range(n):
    s_in = input()[:-1]
    s_len = len(s_in)
    flag = 0
    for i in range(s_len):
        if s_in[i] == 'A':
            if i == s_len-1:
                a_end_num += 1
            flag = 1
        elif s_in[i] == 'B':
            if i == 0:
                b_start_num += 1
            if flag == 1:
                cnt += 1
            flag = 0
        else:
            flag = 0
if b_start_num == n:
    b_start_num -= 1
print(cnt+min(a_end_num, b_start_num))