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# (.NET Core 3.1.201) (judge verdict: Wrong Answer)

using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Text;


class Program
{
    static void Main(string[] args)
    {
        // 入力
        //var s = Console.ReadLine();
        long n = long.Parse(Console.ReadLine());
        string[] s = new string[n];
        for (long i = 0; i < n; i++)
        {
            s[i] = Console.ReadLine();
        }

        long ans = 0;
        for (long i = 0; i < n; i++)
        {
            var tmp = s[i].Replace("AB", "");
            if (tmp.Length < s[i].Length) ans += (s[i].Length - tmp.Length) / 2;
        }

        long a = 0;
        long b = 0;
        long x = 0;
        for (long i = 0; i < n; i++)
        {
            if (s[i][s[i].Length - 1] == 'A') a++;
            if (s[i][0] == 'B') b++;
            if (s[i][s[i].Length - 1] == 'A' && s[i][0] == 'B') x++;
        }

        if (a == b && b == x) ans += a - 1;
        else if(a != b && x == 0) ans += Math.Min(a, b);

        // 出力
        Console.WriteLine(ans);
    }
}