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()
    {
        var N = Int32.Parse(Console.ReadLine());
        var count = 0L;
        var firstB = 0;
        var lastA = 0;
        var ba = 0;
        for (int i=0;i<N;++i)
        {
            var str = Console.ReadLine();
            if (str[0] == 'B') firstB++;
            if (str[str.Length-1] == 'A') lastA++;
            if (str[0] == 'B' && str[str.Length - 1] == 'A') ba++;
            var beforeLetter = str[0];
            for (int j=1;j<str.Length;++j)
            {
                if (beforeLetter == 'A' && str[j] == 'B') count++;
                beforeLetter = str[j];
            }
        }
        if (ba == firstB && ba == lastA) firstB--;
        count += Math.Max(0,Math.Min(firstB,lastA));
        Console.WriteLine(count);
    }
}