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;
using System.Text;
using System.Threading.Tasks;
public class ABC
{
    public static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        int B_start = 0, A_end = 0, both = 0, ABs = 0;

        for (int i = 0; i < N; i++)
        {
            string temp = Console.ReadLine();
            if (temp.StartsWith("B") && temp.EndsWith("A"))
            {
                both++;
            }
            else if (temp.StartsWith("B"))
            {
                B_start++;
            }
            else if (temp.EndsWith("A"))
            {
                A_end++;
            }

            int length_temp = temp.Length;
            temp = temp.Replace("AB", "");
            ABs += (length_temp - temp.Length) / 2;



        }
        long output = 0;
        int min_AB = Math.Min(A_end, B_start);
        output += min_AB;
        A_end -= min_AB;
        B_start -= min_AB;

        if (A_end + B_start >= both)
        {
            output += both;
        }
        else
        {
            //mendoi
            output += A_end + B_start;
            output += both / 2;



        }
        output += ABs;
        Console.WriteLine(output);

    }
}