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)]
ans=0
ab=a=b=0
for ss in s:
  ans+=ss.count("AB")
  if ss[0]=="B" and ss[-1]=="A":
    ab+=1
  elif ss[0]=="B" and ss[-1]!="A":
    b+=1
  elif ss[0]!="B" and ss[-1]=="A":
    a+=1
# print(ans)
cnt_min=min(a,b)
if ab==0:
  ans+=cnt_min
else:
  if a+b>0:
    ans+=ab+cnt_min
  else:
    ans+=ab-1
print(ans)