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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.*;

public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        String[] s = new String[n];
        for (int i = 0; i < n; i++) {
            s[i] = sc.next();
        }
        sc.close();

        // 主処理
        int count = 0;
        int countStartB = 0;
        int countEndA = 0;
        int countStartBEndA = 0;
        for (int i = 0; i < n; i++) {
            if (s[i].startsWith("B")) {
                countStartB++;
                if (s[i].endsWith("A")) {
                    countStartBEndA++;
                }
            }
            if (s[i].endsWith("A")) {
                countEndA++;
            }
            count += (s[i].length() - s[i].replace("AB", "").length()) / 2;
        }
        int CountJoinAB = Math.min(countEndA, countStartB);
        if ((countEndA == countStartB && CountJoinAB == countStartBEndA) || n == CountJoinAB) {
            CountJoinAB--;
        }
        int result = count + CountJoinAB;

        // 出力
        System.out.println(result);
    }
}