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;
using System.Collections.Generic;
using System.Linq;
class Program{
static void Main(string[] args){
var N = int.Parse(Console.ReadLine());
//var list=new List<string>();
int ans=0;
int a=0;
int b=0;
int ab=0;
for(int i=0;i<N;i++){
    var s=Console.ReadLine();
    ans+=s.CountOf("AB");
    if(s[s.Length-1]=='A') a+=1;
    if(s[0]=='B') b+=1;
    if(s[s.Length-1]=='A'&&s[0]=='B') ab+=1;
}
a=a-ab;
b=b-ab;
ans+=Math.Min(a,b);
if(ab!=0){
ans+=ab-1;
if(a!=b)ans+=1;
}

Console.WriteLine(ans);

}
}
public static partial class StringExtensions{

  /// <summary>
  /// 指定した文字列がいくつあるか
  /// </summary>
  public static int CountOf(this string self, params string[] strArray){
    int count = 0;

    foreach (string str in strArray) {
      int index = self.IndexOf (str, 0);
      while (index != -1) {
        count++;
        index = self.IndexOf (str, index + str.Length);
      }
    }

    return count;
  }

}