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)

# -*- coding: utf-8 -*-


def main():
    n = int(input())
    s = [input() for _ in range(n)]
    ans = 0
    back_a_count = 0
    front_b_count = 0
    front_b_back_a_count = 0

    for si in s:
        if si[0] == 'B' and si[-1] == 'A':
            front_b_back_a_count += 1
        elif si[0] == 'B':
            front_b_count += 1
        elif si[-1] == 'A':
            back_a_count += 1

        if len(si) >= 3:
            for j in range(len(si) - 1):
                if (si[j] == 'A' and si[j + 1] == 'B'):
                    ans += 1

    if back_a_count >= front_b_count:
        ans += front_b_count
        back_a_count -= front_b_count
        front_b_count = 0
    else:
        ans += back_a_count
        front_b_count -= back_a_count
        back_a_count = 0

    ans += front_b_back_a_count // 2
    front_b_back_a_count %= 2

    if front_b_back_a_count == 1:
        if back_a_count >= 1:
            ans += 1
            back_a_count -= 1
        elif front_b_count >= 1:
            ans += 1
            front_b_count -= 1

    if back_a_count >= 1:
        ans += 1
    elif front_b_count >= 1:
        ans += 1

    print(ans)


if __name__ == '__main__':
    main()