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: Accepted)

import java.util.Scanner;

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

		int cntFirstB = 0;
		int cntLastA = 0;
		int cntAB = 0;
		int cntFirstBLastA = 0;
		int answer = 0;

		for (int i = 0; i < N; i++) {
			String s = sc.next();
			if (s.charAt(0) == 'B')
				cntFirstB++;
			if (s.charAt(s.length() - 1) == 'A')
				cntLastA++;
			if (s.charAt(0) == 'B' && s.charAt(s.length() - 1) == 'A')
				cntFirstBLastA++;
			int startId = s.indexOf("AB");
			while (startId != -1) {
				cntAB++;
				startId = s.indexOf("AB", startId + 2);
			}
		}
		if (cntFirstBLastA > 0 && cntFirstBLastA == cntFirstB && cntFirstBLastA == cntLastA)
			answer = cntAB + cntFirstBLastA - 1;
		else
			answer = cntAB + Math.min(cntFirstB, cntLastA);
		sc.close();
		System.out.println(answer);
	}
}