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 Rust (1.15.1) (judge verdict: Accepted)

pub fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

pub fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}

pub fn read_vec2<T: std::str::FromStr>(n: usize) -> Vec<Vec<T>> {
    (0..n).map(|_| read_vec()).collect()
}

pub fn read_col<T: std::str::FromStr>(n: usize) -> Vec<T> {
    (0..n).map(|_| read()).collect()
}

use std::cmp::min;

fn main() {
    let n: usize = read();
    let mut sa = 0;
    let mut bs = 0;
    let mut bsa = 0;
    let mut ans = 0;
    for _ in 0..n {
        let s: String = read();
        let c: Vec<char> = s.chars().collect();
        let l = c.len();
        for i in 1..l {
            if c[i - 1] == 'A' && c[i] == 'B' {
                ans += 1;
            }
        }
        if c[0] == 'B' {
            if c[l - 1] == 'A' {
                bsa += 1;
            } else {
                bs += 1;
            }
        } else if c[l - 1] == 'A' {
            sa += 1;
        }
    }

    if sa > 0 || bs > 0 {
        ans += bsa + min(sa, bs);
    } else if bsa > 0 {
        ans += bsa - 1;
    }

    println!("{}", ans);
}