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.BufferedReader;
import java.io.InputStreamReader;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
        int N = scan.nextInt();
        String[] list = new String[N];
        int answer = 0;
        boolean[] firstB = new boolean[N];
        boolean[] lastA = new boolean[N];
        int firstmatchcount = 0;
        int lastmatchcount = 0;
        int bothmatchcount = 0;
        for (int i = 0; i < N; i++) {
            String temp = scan.next();
            list[i] = temp;
            int count = 0;
            boolean foundA = false;
            char[] data = temp.toCharArray();
            if (data[0] == 'B') {
                firstB[i] = true;
                firstmatchcount += 1;
            }
            if (data[data.length-1] == 'A') {
                lastA[i] = true;
                lastmatchcount += 1;
            }
            if (data[0] == 'B' && data[data.length - 1] == 'A') {
                bothmatchcount += 1;
            }
            for(char c : temp.toCharArray()) {
                if (c == 'A') {
                    foundA = true;
                    continue;
                }
                if (!foundA) {
                    continue;
                }
                if (c == 'B') {
                    count += 1;
                }
                foundA = false;
            }
            answer += count;
        }
        int add = 0;
        if (firstmatchcount < lastmatchcount) {
            add = firstmatchcount;
        } else if (lastmatchcount < firstmatchcount) {
            add = lastmatchcount;
        } else {
            add = lastmatchcount;
            if (bothmatchcount == lastmatchcount) {
                add = lastmatchcount - 1;
            }
        }
        answer += Math.min(add, N - 1);
        System.out.println(answer);
    }
}