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();
		String [] S = new String [n];
		
		int c_a = 0;
		int c_b = 0;
		int c_ab = 0;
		int count = 0;
		
		for (int i = 0; i<n; i++){
			S [i] = sc.next();
			
			if (S[i].charAt(0)=='B' && S[i].charAt(S[i].length()-1)=='A'){
				c_ab++;
			}

			if (S[i].charAt(0)=='B')
				c_b++;
			
			if (S[i].charAt(S[i].length()-1)=='A')
				c_a++;
			
			int j = 0;
			while (j<S[i].length()-1){
				if (S[i].charAt(j)!='A'){
					j++;
				}
				else {
					if (S[i].charAt(j+1) =='B'){
						count++;
						j++;
					}
					else
						j++;
				}
			}
		}
		sc.close();
		
		if (c_a==c_ab || c_b==c_ab)
			System.out.println(count+c_ab-1);
		else
			System.out.println(count+Math.min(c_a, c_b));
	}
	

}