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 D

{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            string[] s = new string[N];
            int def = 0;
            List<int> abc = new List<int>();
            abc.Add(0); abc.Add(0);
            int c = 0;
            for (int i = 0; i < N; i++)
            {
                s[i] = Console.ReadLine();
                string buf = s[i].Replace("AB", "");
                def += (s[i].Count() - buf.Count()) / 2;
                if (s[i][s[i].Length - 1] == 'A')
                {
                    if (s[i][0] == 'B')
                    {
                        c++;
                    }
                    else { abc[0]++; }
                }
                else if (s[i][0] == 'B')
                {
                    abc[1]++;
                }
            }
            abc.Sort((a, b) => b - a);

            int min = Math.Min(abc[1], c);
            def += min*2;
            abc[0] -= min;
            abc[1] -= min;
            c -= min;
            if (abc[1] == 0)
            {
             //   if (abc[0] >= c)
                {
                    Console.WriteLine(c + def);
                }
           //     else { Console.WriteLine(c - 1 + def); }
            }
            else if(c==0)
            {
                Console.WriteLine(def+abc[1]);
            }
        }
    }
}