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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

// inputに入力データ全体が入る
function Main(input) {
  // 1行目がinput[0], 2行目がinput[1], …に入る
  input = input.split("\n");
  tmp0 = input[0].split(" ");
  N = Number(input[0]);

  var ans = 0;
  var lastA_cnt = 0;
  var firstB_cnt = 0;
  var firstB_lastA_cnt = 0;
  for (var i = 1; i <= N; i++) {
    var s = input[i];
    ab_cnt = (s.match(/AB/g) || []).length;
    ans += ab_cnt;
    if (s[0] === "B" && s[s.length - 1] === "A") {
      firstB_lastA_cnt++;
      continue;
    }
    ///
    if (s[0] === "B") {
      firstB_cnt++;
    }
    if (s[s.length - 1] === "A") {
      lastA_cnt++;
    }
  }
  ans += firstB_lastA_cnt - 1;
  if (firstB_lastA_cnt > 0) {
    firstB_cnt++;
    lastA_cnt++;
  }
  ans += Math.min(firstB_cnt, lastA_cnt);

  console.log(ans);
}
//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
// Main("4\nXA\nBA\nBA\nBX");