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)

def task_c():
    n = int(input())
    sss = [input().strip() for _ in range(n)]
    
    def count_ab(tt):
        c = 0
        for i in range(1, len(tt)):
            if tt[i-1:i+1] == 'AB':
                c += 1
        return c
    
    c_first_b = sum(1 for ss in sss if ss[:1] == 'B' and ss[-1:] != 'A')
    c_last_a = sum(1 for ss in sss if ss[:1] != 'B' and ss[-1:] == 'A')
    c_ab = sum(1 for ss in sss if ss[:1] == 'B' and ss[-1:] == 'A')
    c_include_ab = sum(count_ab(ss) for ss in sss)
    c = min(c_first_b+c_ab, c_last_a+c_ab) + c_include_ab
    if c_first_b == 0 and (c_first_b+c_ab == c_last_a+c_ab):
        c -= 1
    if c_last_a == 0 and (c_first_b+c_ab == c_last_a+c_ab):
        c -= 1
    print(c)
    
task_c()