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 Scala (2.11.7) (judge verdict: Wrong Answer)

object Main {

    def main(args: Array[String]): Unit = {
      import scala.io.StdIn._
      val N = readLine().toInt
      val s: List[String] = (0 until N).map(_ => readLine()).toList

      var c = 0
      var lastA = 0
      var firstB = 0
      s foreach { str =>
        if (str.head == 'B')
          firstB += 1
        if (str.last == 'A')
          lastA += 1
        str.sliding(2).foreach {
          case "AB" =>
            c += 1
          case _ => // no-op
        }
      }
      c += Math.min(lastA, firstB)
      println(c)
    }

}