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;

class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int ans = 0;
        int startWith = 0;
        int endWith = 0;
        int b_any_a = 0;
        int n = sc.nextInt();
        for(int i = 0;i < n;i++){
            String str = sc.next();
            for(int x = 0;x < str.length()-1;x++){
                if(str.substring(x,x+2).equals("AB")) ans++;
            }
            if(str.charAt(0) == 'B' & str.charAt(str.length()-1) == 'A'){
                b_any_a++;
            }else{
                if(str.charAt(0) == 'B') startWith++;

                if(str.charAt(str.length()-1) == 'A') endWith++;
            } 
        }

        if(b_any_a == 0){
            ans+=Math.min(startWith,endWith);
        }else if(startWith + endWith == 0){
            ans += b_any_a - 1;
        }else if(startWith + endWith > 0){
            ans += b_any_a + Math.min(startWith,endWith);
        }

        System.out.println(ans);
    }
}