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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args: Array<String>) {
  val n = readLine()!!.toInt()
  val segments = Array(n, { readLine()!! })
  val baseCount = segments.sumBy { countAB(it) }
  val endsAList = (0 until n).filter { segments[it].last() == 'A' }
  val startsBList = (0 until n).filter { segments[it][0] == 'B' }
  var bonus = Math.min(endsAList.size, startsBList.size)
  if (bonus > 0 && endsAList == startsBList) {
    bonus--
  }
  println(baseCount + bonus)
}

fun countAB(s: String): Int {
  var count = 0
  for (i in 0 until s.length - 1) {
    if (s[i] == 'A' && s[i + 1] == 'B') {
      count++
    }
  }
  return count
}