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


class Program
{
  void Solve()
  {
    int N = int.Parse(Console.ReadLine());
    int ret = 0;
    int A = 0;
    int B = 0;
    int BA = 0;
    for (int i=0;i<N;i++ )
    {
      var s = Console.ReadLine();

      for(int ii=0;ii<s.Length-2 ;ii++)
      {
        if (s[ii] == 'A' && s[ii + 1] == 'B')
          ret++;
      }
      if (s[0] == 'B' && s[s.Length - 1] == 'A')
        BA++;

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

    }

    ret += Math.Min(A, B);

    if (BA>0&&BA == A && BA == B)
      ret -= 1;

    Console.WriteLine(ret);
  }

  static void Main(string[] args)
  {
    new Program().Solve();
  }
}