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 = "";
		long[] AB = new long[3];
		long sum = 0;
		
		for(int i = 0; i < N; i++) {
			s = sc.next();
			if(s.charAt(0) == 'B' && s.charAt(s.length() - 1) != 'A') {
				AB[0]++;
			} else if(s.charAt(0) != 'B' && s.charAt(s.length() - 1) == 'A') {
				AB[1]++;
			} else if(s.charAt(0) == 'B' && s.charAt(s.length() - 1) == 'A') {
				AB[2]++;
			}
			for(int j = 0; j < s.length() - 1; j++) {
				if(s.substring(j, j + 2).equals("AB")) {
					sum++;
				}
			}
		}
		long a = Math.min(AB[0], AB[1]);
		AB[0] -= a;
		AB[1] -= a;
		sum += a;
		
		long b = 0;
		if(AB[0] >= AB[1]) {
			b = Math.min(AB[0], AB[2]);
			AB[0] -= b;
			AB[2] -= b;
		} else {
			b = Math.min(AB[1], AB[2]);
			AB[0] -= b;
			AB[2] -= b;
		}
		sum += b;
		
		long c = 0;
		
		if(AB[2] > 0) {
			c = AB[2];
		}
		sum += c;
		System.out.println(sum);
	}
}