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)

function ab_count(array){
  var result=0;
  for(var i=0;i<array.length-1;i++){
    if(array[i]=='A' && array[i+1]=='B'){result++;}
  }
  return result;
}

function main(input){
  const lines = input.split('\n');
  const N = lines[0].split(' ').map(x => parseInt(x))[0];
  lines.shift();
  const S = lines;

  var result = 0;
  var head=0;
  var tail=0;
  var sum=0;
  for(var i=0;i<N;i++){
    var current_s = S[i].split('');
    if(current_s[0]=='B'){head++;}
    if(current_s[current_s.length-1]=='A'){tail++;}
    if(current_s[0]=='B' || current_s[current_s.length-1]=='A'){sum++;}
    result += ab_count(current_s);
//    console.log([current_s,ab_count(current_s)]);
  }
  const addition = Math.min(tail,head, sum-1)

  console.log(result+addition);
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));