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)

n = int(input())
ss = []
for i in range(n):
    ss.append(input())

bss = []
ass = []
css = []
for s in ss:
    if s[0] == 'B':
        bss.append(s)
    elif s[-1] == 'A':
        ass.append(s)
    else:
        css.append(s)

ans = ''
while len(bss) > 0 and len(ass) > 0:
    ans += ass[-1] + bss[-1]
    ass.pop()
    bss.pop()
while len(ass) > 0:
    ans += ass[-1]
    ass.pop()
while len(bss) > 0:
    ans += bss[-1]
    bss.pop()
while len(css) > 0:
    ans += css[-1]
    css.pop()

n = 0
p = 0
while p != -1:
    p = ans.find('AB', p)
    if p == -1:
        break
    n += 1
    p += 1

print(n)