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 Atcoder
{
    class Program
    //diverta 2019 Programming Contest C - AB Substrings
    {
        private static void Main(string[] args)
        {
            var n = int.Parse(Console.ReadLine());
            var lines = new string[n];
            var count = 0;
            var countA = 0;
            var countB = 0;
            var countBA = 0;

            for (var i = 0; i < n; i++)
            {
                lines[i] = Console.ReadLine();
                count += (lines[i].Length - lines[i].Replace("AB", "").Length)/2;
                if (lines[i].Substring(0, 1) == "B" && lines[i].Substring(lines[i].Length - 1, 1) == "A")
                {
                    countBA++;
                }
                if (lines[i].Substring(0, 1) == "B")
                {
                    countB++;
                }
                if (lines[i].Substring(lines[i].Length-1, 1) == "A")
                {
                    countA++;
                }
            }

            count += Math.Min(countB, countA);
            if (countB == countA && countBA == countB)
            {
                count--;
            }

            Console.WriteLine(count);
        }
    }
}