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) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int ans = 0;
		String[] s = new String[n];
		int cnt1 = 0;
		int cnt2 = 0;
		int cnt3 = 0;
		for(int i = 0; i < n; i++) {
			s[i] = sc.next();
			if(s[i].substring(0, 1).equals("B") &&s[i].substring(s[i].length()-1, s[i].length()).equals("A")) {
				cnt1 ++;
			}else if(s[i].substring(0, 1).equals("B")) {
				cnt2 ++;
			}else if(s[i].substring(s[i].length()-1, s[i].length()).equals("A")) {
				cnt3 ++;
			}
		}
		if(cnt1 == 0) {
			ans += cnt1 + Math.min(cnt2, cnt3);
		}else if(cnt2 + cnt3!= 0) {
			ans += cnt1 + Math.min(cnt2, cnt3);
		}else {
			ans += cnt1-1;
		}
		String[] t = new String[n];
		for(int i = 0; i < n; i++) {
			t[i] = s[i];
			t[i] = t[i].replace("AB", "X");
			ans += s[i].length() - t[i].length();
		}
		System.out.println(ans);
		sc.close();
	}
}