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 PyPy3 (2.4.0) (judge verdict: Accepted)

import sys
from operator import itemgetter
from collections import deque
sys.setrecursionlimit(10*5)

ans=0
p,q,r=0,0,0
n=int(input())
s=[]
for i in range(n):
    a=input()
    st=a[0]
    ed=a[-1]
    ans+=a.count('AB')
    if st=='B' and ed=='A':
        p+=1
    elif ed=='A':
        q+=1
    elif st=='B':
        r+=1
if q>0 and r>0:
    ans+=max(0, p+1+min(q-1,r-1) )
elif q==0:
    ans+=max(0, p-1 +(1 if r>0 else 0) )
elif r==0:
    ans+=max(0, p-1 +(1 if q>0 else 0) )
    
print(ans)