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: Accepted)

'use strict'
function main(input) {
  input = input.trim().split('\n')
  input.shift()
  let count = 0
  let firstB = 0
  let lastA = 0
  let bothAB = 0
  input.forEach(val => {
    let match = val.match(/AB/g)
    if (match) count += match.length
    let matchB = val.match(/^B/)
    let matchA = val.match(/A$/)
    if (matchB) firstB++
    if (matchA) lastA++
    if (matchA && matchB) bothAB++
  })
  let min = Math.min(lastA, firstB)
  if (lastA === firstB && lastA === bothAB && min > 0) min--
  console.log(count + min)
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));