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;

const int maxn = 11000;

string str[maxn];
string s;
char tmp[maxn];
bool vis[maxn];

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	int n; cin >> n;
	int ans = 0;
	for(int i = 0; i < n; ++ i) {
		cin >> s;
		int l = 0;
		for(int i = s.length() - 1; i >= 0; -- i) {
			if(i && s[i] == 'B' && s[i - 1] == 'A') {
				++ ans;
				-- i;
			}
			else tmp[l ++] = s[i];
		}
		tmp[l] = 0;
		reverse(tmp, tmp + l);
		str[i] = tmp;
	}
	int ac = 0, bc = 0, cnt = 0;
	for(int i = 0; i < n; ++ i) {
		if(str[i].length()) {
			bool flag = true;
			if(str[i][0] == 'B') ++ bc;
			else flag = false;
			if(str[i][str[i].length() - 1] == 'A') ++ ac;
			else flag = false;
			if(flag) ++ cnt;
		}
	}
	if(ac != bc) ans += min(ac, bc);
	else {
		if(cnt == ac) ans += ac - 1;
		else ans += ac;
	}
	cout << ans;
	return 0;
}
/*
5
CA
BA
AB
AB
B
*/