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
# Your code here!

N = int(input())

count_AB = 0
count_last_A = 0
count_first_B = 0
count_both = 0
for i in range(N):
    s = input().rstrip()
    
    count_AB += len(s.split('AB')) - 1
    
    if s[0] == 'B' and s[-1] == 'A':
        count_both += 1
    elif s[0] == 'B':
        count_first_B += 1
    elif s[-1] == 'A' :
        count_last_A += 1
        
max_AB = max(count_last_A, count_first_B)
min_AB = max(count_last_A, count_first_B)

temp = 0
if count_both > 0:
    temp += count_both - 1
    count_both = 1
    
    if max_AB > 0:
        temp += 1
        count_both = 0
        max_AB -= 1
        min_AB += 1
        
if count_both == 0:
    temp += min(count_last_A, count_first_B)
    
print(count_AB + temp)