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: Accepted)

#include<bits/stdc++.h>
#define int long long
using namespace std;

signed main() {
	bool kata = false;
	int n;
	cin >> n;
	vector<string> v(n);
	for (int i = 0; i < n; ++i)cin >> v[i];
	int ab = 0;
	int aend = 0;
	int bstart = 0;
	for (string s : v) {
		for (int i = 1; i < s.size(); ++i) {
			if (s[i - 1] == 'A' && s[i] == 'B')++ab;
		}
		if (s[0] == 'B') ++bstart;
		if (s.back() == 'A')++aend;
		if ((s[0] == 'B') ^ (s.back() == 'A'))kata = true;
	}
	if (kata)cout << ab + min(aend, bstart) << endl;
	else cout << ab + max(0ll, aend - 1) << endl;
}