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;

namespace div2019c
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            //List<string> sl = new List<string>();

            int count, counta, countb,countab;
            count = counta = countb = countab =0;

            for(int i = 0; i < N; i++)
            {
                string tmps = Console.ReadLine();
                int ret = 0;
                for(; ; )
                {
                    ret = tmps.IndexOf("AB", ret);
                    if(ret >= 0)
                    {
                        count++;
                        ret++;
                    }
                    else
                    {
                        break;
                    }

                }
                if ((tmps[0] == 'B') && (tmps[tmps.Length - 1] == 'A'))
                {
                    countab++;
                }else if (tmps[0] == 'B')
                {
                    countb++;
                }else if(tmps[tmps.Length-1] == 'A')
                {
                    counta++;
                }

            }
            /*
            Console.WriteLine(count);
            Console.WriteLine(counta);
            Console.WriteLine(countb);
            Console.WriteLine(countab);
            Console.WriteLine("--");
            */
            int tmpb = countb;
            for (int i = 0; i < countab; i++)
            {
                int tmpa = counta;
                if(counta <= countb)
                {
                    counta++;
                }
                if (tmpa >= countb)
                {
                    countb++;
                }
            }

            if(counta == countb && tmpb==0 && count>0)
            {
                count--;
            }
            /*
            Console.WriteLine(counta);
            Console.WriteLine(countb);
            Console.WriteLine("--");
            */
            Console.WriteLine(count + Math.Min(counta, countb));
            Console.ReadLine();

        }
    }
}