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: Accepted)

# -*- coding: utf-8 -*-
import sys

#読み込み
n = int(input())

strs = []

for i in range(n):
    strs.append(input())

#文字列の確認
str_in_num = 0
str_both_ab = 0
str_head_a = 0
str_tail_b = 0

for st in strs:
    #文字列中にABを含むもの
    #print(st)
    if len(st) > 2:
        str_in_num += st[0:-1].count('AB')

    #文字列の先頭がBのもの
    if st[-1] == 'A' and st[0] == 'B':
        str_both_ab += 1
    else:
        if st[-1] == 'A':
            str_head_a += 1

        if st[0] == 'B':
            str_tail_b += 1

total = 0

if str_both_ab > 0:
    total += (str_both_ab - 1)

    if str_head_a > 0:
        total += 1
        str_head_a -= 1
    if str_tail_b > 0:
        total += 1
        str_tail_b -= 1

total += str_in_num
total += min(str_head_a, str_tail_b)

print(total)