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: Wrong Answer)

fun main(args : Array<String>) {
    val n = readLine()!!.toInt()

    var bStart = 0
    var aEnd = 0
    var both = 0
    var cnt = 0

    val regex = "(AB)".toRegex()

    repeat(n) {
        val s = readLine()!!
        cnt += regex.findAll(s).count()
        if (s[0] == 'B' && s[s.length-1] == 'A') {
            both++
        } else if (s[0] == 'B') {
            bStart++
        } else if (s[s.length-1] == 'A') {
            aEnd++
        }
    }

    cnt += Math.min(bStart, aEnd)
    cnt += Math.min(Math.abs(bStart-aEnd), both)
    both -= Math.abs(bStart-aEnd)
    cnt += both

    println(cnt)
}