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)

'use strict'

function Main(input) {
  const G = input.split("\n").slice(1)

  let ans = 0
  let startB = 0
  let endA = 0
  let bothAB = 0

  for (let str of G) {
    ans += (str.split("AB")).length - 1
    if (str.substr(0, 1) === "B" && str.substr(-1, 1) === "A") {
      bothAB++
    } else if (str.substr(0, 1) === "B") {
      startB++
    } else if (str.substr(-1, 1) === "A") {
      endA++
    }

    if (bothAB > 0) {
      if ((startB > 0 || endA > 0) || bothAB > 1) {
        bothAB--
        startB++
        endA++
      }
    }

    while (startB > 0 && endA > 0) {
      startB--
      endA--
      ans++
    }
  }
  
  console.log(ans)
}

Main(require("fs").readFileSync("/dev/stdin", "utf8").trim())