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 PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
class MyTest {
 
    private function getInput() {
        while (!empty($input = fgets(STDIN))) {
            $ret[] = trim($input);    
        }
        return $ret;
    }
 
    private function main($input) {
        $ret = 0;
        $countA = 0;
        $countB = 0;
        $x = 0;
        foreach ($input as $val) {
            $ret += substr_count($val, 'AB');
            if (strpos(substr($val, -1), 'A') === 0) {
                $countA += 1;
            }
            if (strpos($val, 'B') === 0) {
                $countB += 1;
            }
            if (strpos(substr($val, -1), 'A') === 0 && strpos($val, 'B') === 0) {
                $x += 1;
            }
        } 
        $join = min($countA, $countB);
        
        if ($x > 0 && $countA == 0 && $countB == 0) {
            $join -= 1;
        } 
        $ret += $join;
        echo "{$ret}\n";
    }
 
    public function run() {
        $input = self::getInput();
        self::main($input);
    }
    
}
 
MyTest::run();