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() {
  ios::sync_with_stdio(0);
  cin.tie(0);

  int N;
  cin >> N;
  vector<string> a(N);
  int aa = 0, bb = 0, cc = 0, dd = 0;
  for (auto &x : a) {
    cin >> x;
    if (x.back() == 'A' && x[0] == 'B') {
      ++dd;
    } else {
      aa += (x.back() == 'A');
      bb += (x[0] == 'B');
    }
    for (int i = 0; i < (int) x.size() - 1; ++i) {
      if (x[i] == 'A' && x[i + 1] == 'B') {
        ++cc;
      }
    }
  }

  cout << cc + min(aa, bb) + (dd - 1) << '\n';
}