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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;

int main(){
  int N;
  cin >> N;
  
  int Anum = 0, Bnum = 0, ABnum = 0, ans = 0;
  for (int i = 0; i < N; i++){
    string S;
    cin >> S;
    
    for (int j = 0; j < S.size() - 1; j++){
      if (S.at(j) == 'A' && S.at(j + 1) == 'B'){
        ans++;
      }
    }
    
    if (S.at(S.size() - 1) == 'A'){
      
      if (S.at(0) == 'B'){
        ABnum++;
      }
      else{
        Anum++;
      }
      
    }
    else{
    
      if (S.at(0) == 'B'){
        Bnum++;
      }
      
    }
    
  }
  
  ans += min(Anum, min(Bnum, N - 1));
  if (ABnum > 0){
    if (max(Anum, Bnum) > 0){
      ans += ABnum;
    }
    else{
      ans += ABnum - 1;
    }
  }
  cout << ans << endl;
}