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;

public class CSharp
{
    public static void Main()
    {
        Kyopuro chokudai = new Kyopuro();
        chokudai.AtCoder();
    }
}

public class Kyopuro
{
    public void AtCoder()
    {
        string[] input;
        input = Console.ReadLine().Split(' ');

        int n;
        n = int.Parse(input[0]);
        string[] s = new string[n];
        int t = 0;
        int ans = 0;
        int x = 0;
        int y = 0;
        int z = 0;

        for (int i = 0; i < n; i++)
        {
            s[i] = Console.ReadLine();
            t = s[i].Length;
            for (int j = 1; j < t; j++)
            {
                if (s[i][j - 1] == 'A' && s[i][j] == 'B') ans++;
            }
            if (s[i][0] == 'B')
            {
                if (s[i][t - 1] == 'A') z++;
                else y++;
            }
            else
            {
                if (s[i][t - 1] == 'A') x++;
            }
        }
        DebugWL(x + " " + y + " " + z);
        bool f = false;
        if (x == 0 && y == 0) f = true;

        t = Math.Min(x, y);
        ans += t;
        x = Math.Max(x - t, 0);
        y = Math.Max(y - t, 0);

        t = Math.Max(x, y);
        ans += Math.Min(z, t);
        if (z > t)
        {
            ans += z - t;
            if (f && ans > 0) ans--;
        }

        Console.WriteLine(ans);
    }
    public static void DebugWL(object x) { System.Diagnostics.Debug.WriteLine(x); }
}