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 diverta_B
{
    class Program
    {
        static void Main(string[] args)
        {
            var n = long.Parse(Console.ReadLine());
            string[] s = new string[n];
            var count = 0;
            var aback = 0;
            var bfront = 0;
            for (int i = 0; i < n; i++)
            {
                s[i] = Console.ReadLine();
                for (int j = 0; j < s[i].Length-1; j++)
                {
                    if (s[i].Substring(j, 2) == "AB")
                    {
                        count++;
                    }   
                }
                if (s[i].Substring(0,1) == "B")
                {
                    bfront++;
                }
                if (s[i].Substring(s[i].Length-1, 1) == "A")
                {
                    aback++;
                }
            }
            if (bfront > aback)
            {
                count = count + aback;
            }
            else
            {
                count = count + bfront;
            }

            if (aback + bfront == 2*n)
            {
                count = count - 1;
            }

            Console.WriteLine(Convert.ToString(count));
            Console.ReadLine();
        }
    }
}