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())
lasta=0
headb=0
spec=0
cnt=0
for _ in range(N):
    s=str(input())
    for i in range(len(s)-1):
        if s[i:i+2]=="AB":
            cnt+=1
    if s[0]=="B" and s[-1]=="A":
        spec+=1
    elif s[-1]=="A":
        lasta+=1
    elif s[0]=="B":
        headb+=1
        
if abs(headb-lasta)>=spec:
    print(min(headb,lasta)+spec+cnt)   
elif lasta==0 and headb==0 and spec>0:
    print(spec-1+cnt)
elif lasta==0 and headb==0 and spec==0:
    print(cnt)
else:
    print(spec-abs(headb-lasta)+max(headb,lasta)+cnt)