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.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        int lB = 0;
        int rA = 0;
        int lrBA = 0;

        int ans = 0;
        for (int i = 0; i < n; i++) {
            String s = sc.next();
            boolean isLeftB = false;
            boolean isRightA = false;
            if (s.charAt(0) == 'B')
                isLeftB = true;
            if (s.charAt(s.length()-1) == 'A')
                isRightA = true;

            if (isLeftB && isRightA)
                lrBA++;
            else if (isLeftB)
                lB++;
            else if (isRightA)
                rA++;

            for (int j = 0; j < s.length(); j++) {
                if (s.indexOf("AB", j) >= 0) {
                    ans++;
                    j = s.indexOf("AB", j);
                } else {
                    break;
                }
            }
        }

        ans += Math.min(lB, rA);
        ans += lrBA;
        if (lB + rA == 0)
            ans--;

        System.out.println(ans);
    }
}