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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)


import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

  public static void main(String[] args) throws FileNotFoundException {

//    Scanner cin = new Scanner(new FileReader("input.txt"));
    Scanner cin = new Scanner(System.in);

    List<String> saved = new ArrayList<>();
    int n = cin.nextInt();

    int res = 0;
    int concateA = 0;
    int concateB = 0;
    for (int i=0;i<n;i++) {
      String line = cin.next();
//      System.out.println(line);
      saved.add(line);
//      System.out.println("len "+line.length());
      if (line.contains("AB"))
        res++;
      if (line.lastIndexOf('A') == line.length()-1)
        concateA++;
      if (line.indexOf('B') == 0)
        concateB++;
    }
//    System.out.println("A "+concateA+" B "+concateB);
    if (concateA==n&&concateB==n) {
      System.out.println(res+n-1);
    }
    else {
      res = res + Math.min(concateA, concateB);
      System.out.println(res);
    }

  }

}