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 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>

int min(int a,int b){
  if(a > b) return b;
  else return a;
}

int main(){
  int n;
  scanf("%d\n",&n);
  char s[n][11];
  int l[n],a,b,c,d;//length,A終わり,B始まり,B~A,s中AB
  for(int i = 0; i < n; ++i) l[i] = 0;
  a = 0;
  b = 0;
  c = 0;
  d = 0;
  int ret,count,flag,flag2;
  for(int i = 0; i < n; ++i){
    count = 0;
    flag = 0;
    flag2 = 0;
    for(int j = 0; j < 11; ++j){
      ret = scanf("%c",&s[i][j]);
      if(ret == EOF || s[i][j] == '\n') break;
      count++;
      if(s[i][j] == 'A') flag = 1;
      else if(flag == 1 && s[i][j] == 'B'){
        d++;
        flag = 0;
      }else flag = 0;
    }
    l[i] = count;
    if(s[i][count-1] == 'A'){
      a++;
      flag2 = 1;
    }
    if(s[i][0] == 'B'){
      b++;
      if(flag2 == 1) c++;
    }
  }
  int answer = d;
  answer += min(a,b);
  if(a == b && a == c) answer -= 1;
  
  printf("%d\n",answer);
  return 0;
}