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)

#!/usr/bin/env python3
n = int(input())
s = [input() for _ in range(n)]
tail_a = 0
head_b = 0
both_have = 0
ans = 0
for i in range(n):
    if s[i][0] == "B": head_b += 1
    if s[i][-1] =="A": tail_a += 1
    if s[i][0] == "B" and s[i][-1] =="A":
        both_have += 1
    ans += s[i].count("AB")
ans += min(tail_a,head_b)
if tail_a == head_b and tail_a == both_have:
    if both_have > 0:
        ans -= 1
print(ans)