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 C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;

namespace diverta2019_C
{
    class Program
    {
        static void Main(string[] args)
        {
            var N = int.Parse(Console.ReadLine());
            var s = new string[N];

            var a = 0;
            var b = 0;
            var ab = 0;
            var same = 0;
            var none = 0;
            for (int i = 0; i < N; i++)
            {
                s[i] = Console.ReadLine();
                var flag1 = s[i][0] == 'B';
                var flag2 = s[i][s[i].Length - 1] == 'A';
                if (flag1) b++;
                if (flag2) a++;
                if (flag1 && flag2) same++;
                if (!flag1 && !flag2) none++;
                s[i] = s[i].Replace("AB", "0");
                foreach (var c in s[i])
                {
                    if (c == '0') ab++;
                }
            }
            var n = Math.Min(a, b);
            var max = Math.Max(a, b);
            if (n == same && max == same) n--;
            Console.WriteLine(n + ab);
        }
    }
}