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

public class Hello
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine());
        var ss = new string[n];
        for (int i = 0; i < ss.Length; ++i)
            ss[i] = Console.ReadLine();

        int count = 0;
        int b = 0;
        int a = 0;
        int ba = 0;

        for (int i = 0; i < ss.Length; ++i)
        {
            var s = ss[i];
            var prev = ' ';
            var isB = false;
            for (int j = 0, length = s.Length; j < length; ++j)
            {
                var c = s[j];
                switch (c)
                {
                    case 'B':
                        switch (prev)
                        {
                            case 'A':
                                ++count;
                                break;
                            case ' ':
                                isB = true;
                                break;
                        }
                        break;
                }
                prev = c;
            }
            if (prev == 'A')
            {
                if (isB)
                    ++ba;
                else
                    ++a;
            }
            else if (isB)
                ++b;
        }

        if (b > a)
        {
            var tmp = b;
            b = a;
            a = tmp;
        }

        var adder = b + ba;
        if (a == 0)
            --adder;

        Console.WriteLine(count + adder);
    }
}