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;

int main() {
  int n;
  cin >> n;
  int nab=0,nea=0,nfb=0,eafb=0;
  for(int i=0;i<n;i++) {
    string s;
    cin >> s;
    if(s[0]=='B'&&s[s.size()-1]!='A') nfb++;
    if(s[0]!='B'&&s[s.size()-1]=='A') nea++;
    if(s[0]=='B'&&s[s.size()-1]=='A') eafb++;
    for(int j=0;j<s.size()-1;j++) {
      if(s.substr(j,2)=="AB") nab++;
    }
  }
  int temp=0;
  if(nea+nfb==0) {
    temp+=eafb-1;
  }
  else {
    temp+=eafb+min(nea,eafb);
  }
  cout << nab + temp << endl;
}