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();
		sc.nextLine();

		String[] s = new String[N];

		int ab = 0;
		int b_a = 0;
		int a_end = 0;
		int b_start = 0;
		for(int i=0;i<N;i++) {
			s[i] = sc.nextLine();

			int fromIndex = 0;
			while((fromIndex = s[i].indexOf("AB", fromIndex)) != -1) {
				fromIndex++;
				ab++;
			}

			if(s[i].endsWith("A") && s[i].startsWith("B")) {
				b_a++;
				continue;
			}

			if(s[i].endsWith("A")) a_end++;
			if(s[i].startsWith("B")) b_start++;
		}

		if(b_a > 0) b_a--;
		b_a += Math.min(a_end, b_start);
		if(a_end != b_start) b_a++;

		System.out.println(ab + b_a);
	}

}