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.*;
import java.math.*;
public class Main{

	static   Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		int N = sc.nextInt();
		String str[] = new String[N];
		int countA = 0;
		int countB = 0;
		int count = 0;
		StringBuilder concat = new StringBuilder();
		for (int i = 0; i < N ; i++) {
			str[i] = sc.next();
			if (str[i].endsWith("AB") == false) {
				if (str[i].charAt(0) == 'B') {
					countB++;
				} 
				if (str[i].charAt(str[i].length() - 1) == 'A') {
					countA++;
				}
			}
		}
		count += Math.min(countA, countB);
//		System.out.println(count);
//		System.out.println(countA);
//		System.out.println(countB);
		
		for (String s: str) {
			for (int i = 0; i < s.length() - 1; i++) {
				if (s.substring(i, i + 2).equals("AB")) {
					count++;
				}
			}
		}
		
		String msg = "No";
	
		
		System.out.println(count);

		
	}

}