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)

from sys import stdin
n = int(stdin.readline().rstrip())
li = [stdin.readline().rstrip() for _ in range(n)]
b_sta = 0
a_last = 0
b_a = 0
ab = 0
for i in li:
    ab += i.count("AB")
    if i[0] == "B" and i[-1] == "A":
        b_a += 1
    elif i[0] == "B":
        b_sta += 1
    elif i[-1] == "A":
        a_last += 1
if b_a == 0:
    print(ab+min(a_last,b_sta))
else:
    if a_last + b_sta > 0:
        print(ab+b_a+min(a_last,b_sta))
    else:
        print(ab+b_a-1)