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;
using static System.Console;
using static System.Math;

class Program
{
    static void Main()
    {
        var N = int.Parse(ReadLine());
        var s = new string[N];
        var ans = 0;
        for (int i = 0; i < s.Length; i++)
        {
            s[i] = ReadLine();
            for (int j = 1; j < s[i].Length; j++)
            {
                if (s[i][j - 1] == 'A' && s[i][j] == 'B') ans++;
            }
        }

        var c = 0;
        var a = 0;
        var b = 0;
        var ab = 0;
        for (int i = 0; i < s.Length; i++)
        {
            var l = s[i][0];
            var r = s[i][s[i].Length - 1];
            if (l == 'B' && r == 'A') c++;
            else
            {
                if (l == 'B')
                {
                    b++;
                }
                if (r == 'A')
                {
                    a++;
                }
            }
            if (l == 'A' && r == 'B') ab++;

        }


        if (c == 0)
        {
            ans += Min(a, b);
        }
        else
        {
            ans += c - 1;
            if (a > 0) ans++;
            if (b > 0) ans++;
            ans += Max(Min(a - 1, b - 1), 0);
        }
        WriteLine(ans);

    }
}