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 C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (n); i++)

int main() {
    int n;
    cin >> n;
    vector<string> strs(n);
    int ans = 0;
    int _a = 0, b_ = 0, b_a = 0;
    rep(i, n) {
        cin >> strs[i];
        int m = strs[i].size();
        if(strs[i][0] == 'B' && strs[i][m-1] == 'A'){
            b_a++;
        } else if(strs[i][0] == 'B'){
            b_++;
        } else if(strs[i][m-1] == 'A'){
            _a++;
        }
        for (int j = 0; j < m - 1; j++){
            if(strs[i].substr(j, 2) == "AB"){
                ans++;
            }
        }
    }
    int mini = min(b_, _a);
    if(mini == 0){
        ans += max(b_a, 0);
    } else {
        ans += mini + b_a;
    }
    cout << ans << endl;
}