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)

import numpy as np
N = int(input())
s1 = np.zeros(N)
s2 = np.zeros(N)
s3 = np.zeros(N)
co = 0
for i in range(N):
    si = str(input()).split()[0]
    #print("test",si,si[0][0],si[0][-1])
    s1[i] = (si[0]=='B')
    s2[i] = (si[-1]=='A')
    s3[i] = (s1[i]==1 and s2[i] ==1)
    co += si.count('AB')

as1 = np.sum(s1)
if as1 == N:
    as1 = N-1
as2 = np.sum(s2)
if as2 == N:
    as2 = N-1

if (np.sum(s3) == N-1 ):
    as1 = N-2
    as2 = N-2


Ans = int(co + min(as1,as2))
print (Ans)