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 C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
#include <vector>
#include <algorithm>
#include <climits>
#include <cmath>
#include <map>
#include "boost/multiprecision/cpp_int.hpp"

using ll = long long;
using ull = unsigned long long;
namespace mp = boost::multiprecision;

int main() {

	std::cin.tie(nullptr); std::ios::sync_with_stdio(false);

	int N; std::cin >> N;
	std::vector<std::tuple<char, char>> vec;//ABの数,最初の文字,最後の文字

	int AB_num = 0;//ABの数

	std::map<char, int> map;//最初の文字
	std::map<char, int> map2;//最後の文字

	for (int i = 0; i < N; i++){
		std::string tmp; std::cin >> tmp;
		for (int i = 0; i < tmp.size() - 1; i++)if (tmp[i] == 'A' && tmp[i + 1] == 'B')AB_num++;
		map[tmp[0]]++;
		map2[tmp[tmp.size() - 1]]++;
	}

	int sub_ans = std::min(map2['A'], map['B']);

	if (sub_ans == N)sub_ans--;

	int ans = AB_num + sub_ans;

	std::cout << ans;

	return 0;

}