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)

N = int(input())
s = [input() for i in range(N)]

enda = 0
startb = 0
btoa = 0
ans = 0

for i in s:
    if i[0] == 'B' and i[-1] == 'A':
        btoa += 1
    elif i[-1] =='A':
        enda += 1
    elif i[0] == 'B':
        startb += 1
    ans += i.count('AB')

# print('-a:', enda, 'b-:', startb, 'b-a:', btoa, 'ans:',ans)

if btoa >= 1:
    ans += btoa - 1
    btoa = 1
    if enda > 0 and startb > 0:
        ans += 2
        btoa = 0
        enda -= 1
        startb -= 1
    elif enda > 0:
        ans += 1
        enda -= 1
    elif startb > 0:
        ans += 1
        startb -= 1

if enda < startb:
    enda, startb = startb, enda
ans += startb
enda -= startb
startb = 0

print(ans)