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 <bits/stdc++.h>
using namespace std;

int main(void){
	int n;
	cin >> n;
	vector<string> s(n);
	for(int i = 0; i < n; ++i){
		cin >> s[i];
	}
	long long ans = 0LL;
	int a = 0, b = 0;
	for(int i = 0; i < n; ++i){
		if(s[i].size() == 1){
			if(s[i][0] == 'A'){
				a++;
			}
			if(s[i][0] == 'B'){
				b++;
			}
		}
		for(int j = 0; j < s[i].size()-1; ++j){
			if(j==0 && s[i][j] == 'B'){
				b++;
			}
			if(j==s[i].size()-2 && s[i][j+1] == 'A'){
				a++;
			}
			if(s[i][j]=='A' && s[i][j+1] == 'B'){
				ans++;
			}
		}
	}
	ans += min(a, b);
	cout << ans << endl;
}