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: Accepted)

#include <iostream>
#include <cstring>
using namespace std;

int lastA, firstB;
int AB;
int main() {
  int n;
  int ans = 0;
  cin >> n;
  for(int i = 0; i < n; i++) {
    string s;
    cin >> s;
    for(int j = 0; j < s.size(); j++) {
      if(s[j] == 'A') {
	if(j+1 < s.size() && s[j+1] == 'B') ans++;
      }
    }
    if(s[s.size() - 1] == 'A' && s[0] == 'B') AB++;
       
       else if(s[s.size() - 1] == 'A') lastA++;
       else if(s[0] == 'B') firstB++;
  }
  int tmp;
  if(AB > 0) {
  tmp = AB - 1;
  if(lastA > 0) tmp++, lastA--;
  if(firstB > 0) tmp++, firstB--;
  }
  else tmp = 0;
  cout << tmp + ans + min(firstB, lastA) << endl;
  return 0;
}