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)

#k,a,b=map(int,input().split())
n=int(input())
s=[input() for i in range(n)]
a_count=0
b_count=0
fin_a=0
ini_b=0
ab=0
for i in s:
    if i[0]=='B' and i[-1]=='A':
        ab+=1
    elif i[0]=='B':
        ini_b+=1
    elif i[-1]=='A':
        fin_a+=1

s='+'.join(s)
ans=s.count('AB')
print(ans+min(fin_a+ab,ini_b+ab) if not (ab==1 and fin_a==0 and ini_b==0) else ans)