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;

//関数
//main関数
int main() {
    
    
    //入力
    long N;
    cin>>N;
    vector<string> s(N);
    for(int i=0;i<N;i++){
        cin>>s.at(i);
    }
    //計算
    long ans=0;
    long l=0,r=0;//hasi
    for(int i=0;i<N;i++){
        bool waiting =false;
        for(int j=0;j<s.at(i).size();j++){
            if(s.at(i).at(j)=='B' && waiting) ans++;
            waiting =(s.at(i).at(j)=='A');
        }
        
        if(s.at(i).at(0)=='B'){
            l++;
        }
        if(s.at(i).at(s.at(i).size()-1)=='A'){
            r++;
        }
    }
    //cout<<ans<<endl;
    
    

    
    
    

    //出力
    cout<<ans+min(N-1,min(l,r))<<endl;//" "<<l<<" "<<r<<endl;
}