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.Linq;
using System.Collections.Generic;

class Program
{
    static void Main(string[] args)
    {
        var N = int.Parse(Console.ReadLine());
        var s = new string[N];
        int c1, c2, c3;
        c1 = c2 = c3 = 0;
        int ans = 0;
        var subStr = new System.Text.StringBuilder();
        for (int i = 0; i < N; i++)
        {
            var value = Console.ReadLine();
            s[i] = value;

            var startB = value.StartsWith("B");
            var endA = value.EndsWith("A");
            if (startB && endA)
            {
                c1++;
            }
            else if (startB && !endA)
            {
                c2++;
            }
            else if (!startB && endA)
            {
                c3++;
            }

            for (int j = 0; j < value.Length - 1; j++)
            {
                subStr.Clear();
                subStr.Append(value[j]).Append(value[j + 1]);
                if (subStr.ToString() == "AB") ans++;
            }
        }


        if (c1 == 0)
        {
            ans += Math.Min(c2, c3);
        }
        else if (c2 + c3 == 0)
        {
            ans += c1 - 1;
        }
        else
        {
            ans += c1 + Math.Min(c2, c3);
        }

        Console.WriteLine(ans);
    }
}