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;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();

        String[] str = new String[N];
        int hitCount = 0;
        for (int i = 0; i < N; i++) {
            str[i] = sc.next();
            String[] splitStr = str[i].split("AB");
            hitCount += splitStr.length - 1;
        }

        int countA = 0;
        int countB = 0;
        for (int i = 0; i < N; i++) {
            Pattern pB = Pattern.compile("^B");
            Matcher mB = pB.matcher(str[i]);
            if (mB.find()) {
                countB++;
            }
            Pattern pA = Pattern.compile("A$");
            Matcher mA = pA.matcher(str[i]);
            if (mA.find()) {
                countA++;
            }
        }
        int joinCount = Math.min(countA, countB);

        System.out.println(hitCount + joinCount);
    }
}