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: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        Console.WriteLine(Solve());
        return;
    }

    public static string Solve()
    {
        int N = ReadInt();
        int a = 0;
        int b = 0;
        int ba = 0;
        long cnt = 0;
        for (int i = 0; i < N; i++)
        {
            string str = Read();
            for (int j = 0; j < str.Length - 1; j++)
            {
                if (str[j] == 'A' && str[j + 1] == 'B')
                {
                    j++;
                    cnt++;
                }
            }
            if (str[0] == 'B')
            {
                if (str[str.Length - 1] == 'A')
                {
                    ba++;
                }
                else
                {
                    b++;
                }
            }
            else
            {
                if (str[str.Length - 1] == 'A')
                {
                    a++;
                }
            }
        }
        if (ba > 0)
        {
            cnt += ba - 1;
            if (a > 0)
            {
                a--;
                cnt++;
            }
            if (b > 0)
            {
                b--;
                cnt++;
            }
        }
        cnt += Math.Min(a, b);
        return cnt.ToString();
    }

    private static string Read() { return Console.ReadLine(); }
    private static int ReadInt() { return int.Parse(Read()); }
    private static long ReadLong() { return long.Parse(Read()); }
    private static double ReadDouble() { return double.Parse(Read()); }
    private static int[] ReadInts() { return Array.ConvertAll(Read().Split(), int.Parse); }
    private static long[] ReadLongs() { return Array.ConvertAll(Read().Split(), long.Parse); }
    private static double[] ReadDoubles() { return Array.ConvertAll(Read().Split(), double.Parse); }
}