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 Ruby (2.3.3) (judge verdict: Wrong Answer)


def c_s(str)
    i = -2
    kk = 0
    while 1
        i = str.index('AB', i+2)
        break if i == nil
        kk += 1
    end
    kk
end

aabb = 0
n=gets.split.map(&:to_i)
s=$<.map(&:chomp)
ab = s.map {|ss| c_s(ss)}.inject(:+)
a = s.select {|ss| ss.end_with?('A')}.size
b = s.select {|ss| ss.start_with?('B')}.size
a_b = s.select {|ss| ss.start_with?('B')}.select {|ss| ss.end_with?('A')}.size
if a_b == a && a_b == b
    if s.select {|ss| ss == 'AB'}.size == 0
        aabb = 1 
    end

end
puts ab + ([a,b].min) - aabb