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 solve():
    N = int(input())
    S = [input() for _ in range(N)]

    inner = 0
    for s in S:
        inner += s.count("AB")
    
    B_ended = 0
    A_begin = 0

    A_ended = 0
    B_begin = 0
    both = 0
    for s in S:
        if s[0] == "B": B_begin += 1
        # if s[-1] == "B": B_ended += 1
        # if s[0] ==  "A": A_begin += 1
        if s[-1] == "A": A_ended += 1
        if s[0] == "B" and s[-1] == "A":
            both += 1
    
        
    
    mmA = min(A_ended, B_begin)
    
    # mmB = min(A_begin, B_ended)
    if B_begin == A_ended == both:
        mmA -= 1
    
    print(inner + mmA )
    

if __name__ == "__main__":
    solve()