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;

namespace diverta2019_C
{
    class Program
    {
        static void Main(string[] args)
        {
            var N = int.Parse(Console.ReadLine());
            var count = 0;
            var countA = 0;
            var countB = 0;
            var countAB = 0;

            for (var i = 0; i < N; i++)
            {
                var str = Console.ReadLine();
                var str2 = str.ToCharArray();

                for (var j = 0; j < str2.Length - 1; j++)
                    if (str2[j] == 'A' && str2[j + 1] == 'B')
                        count++;

                if (str2[0] == 'B' && str2[str2.Length - 1] != 'A')
                    countB++;

                if (str2[str2.Length - 1] == 'A' && str2[0] != 'B')
                    countA++;

                if (str2[0] == 'B' && str2[str2.Length - 1] == 'A')
                    countAB++;

            }

            var min = Math.Min(countA, countB);
            Console.WriteLine(count + min + countAB - 1);
        }
    }
}