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;
using System.Collections.Generic;

namespace diverta2019PC {
  class ProblemC {
    static void Main(string[] args) {
      int n = Input.num;
      string[] s = new string[n];
      for (int i = 0; i < n; i++) {
        s[i] = Input.str;
      }
      
      int cnt = 0;
      for (int i = 0; i < n; i++) {
        for (int j = 0; j < s[i].Length - 1; j++) {
          if (s[i].Substring(j, 2) == "AB") {
            cnt++;
          }
        }
      }
      int a = 0, b = 0;
      bool foo = false;
      for (int i = 0; i < n; i++) {
        int c = 0;
        if (s[i].StartsWith("B")) {
          b++; c++;
        }
        if (s[i].EndsWith("A")) {
          a++; c++;
        }
        if (c < 2) {
          foo = true;
        }
        c = 0;
      }
      cnt += Math.Min(a,b);
      if (!foo) cnt--;
      System.Console.WriteLine(cnt);
    }
  }
  public class Input {
    public static string str => System.Console.ReadLine();
    public static string[] strs => str.Split(' ');
    public static char[] charArr => str.ToCharArray();
    public static int num => int.Parse(str);
    public static int[] nums => Array.ConvertAll(strs, int.Parse);
    public static long numL => long.Parse(str);
    public static long[] numLs => Array.ConvertAll(strs, long.Parse);
  }
}