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 (Clang 3.8.0) (judge verdict: Accepted)

#include <iostream>
#include <string>

using namespace std;

int main(){
  int n;
  cin >> n;
  
  int res=0;
  int b=0,a=0,ab=0;
  string s;
  for(int i=0;i<n;i++){
 cin >> s;
  for(int j=0;j<s.length()-1;j++){
   if(s.substr(j,2)=="AB"){
     res++;
   }
  } 
   if(s[0]=='B'&&s[s.length()-1]=='A'){
    ab++;
   }
   else if(s[0]=='B'&&s[s.length()-1]!='A'){
    b++;
   }
   else if(s[0]!='B'&&s[s.length()-1]=='A'){
    a++;
   }
  }  
 
   res+=min(a,b);
   if(a==0&&b==0&&ab!=0){
   ab--;
   }
   res+=ab;
  
 cout << res <<endl;

}