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.Int32;

namespace ConsoleApp1
{
    class Program
    {
        static void Main()
        {
            label:
            int n = Parse(ReadLine());
            int result = 0, a = 0, b = 0, ab = 0;
            for (int i = 0; i < n; ++i)
            {
                var line = ReadLine();
                if (line[line.Length - 1] == 'A')
                {
                    if (line[0] == 'B') ++ab;
                    else ++a;
                }
                else if (line[0] == 'B') ++b;
                for(int j = 0; j < line.Length; ++j)
                {
                    if (line[j] == 'A')
                    {
                        if (j + 1 < line.Length && line[j + 1] == 'B') ++result;
                    }
                }
            }
            if (0 < ab)
            {
                if (0 < a || 0 < b) result += ab;
                else result += ab - 1;
            }
            result += Math.Min(a, b);
            WriteLine(result);
        }
    }
}