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: Accepted)

#include<stdio.h>

int main(){
  int N;

  scanf("%d", &N);

  int end_a = 0, start_b = 0, middle_ab = 0, both_ab = 0, i, j;
  int len;

  char s[15];

  for(i = 0; i < N; i++){
    scanf("%s", s);
    len = strlen(s);
    if(s[0] == 66 && s[len-1] == 65) both_ab++;
    else if(s[0] == 66) start_b++;
    else if(s[len-1] == 65) end_a++;
    for(j = 0; j < len; j++){
      if(s[j] == 65 && s[j+1] == 66) middle_ab++;
    }
  }

  int ans = middle_ab + both_ab;

  if(end_a < start_b) ans += end_a;
  else ans += start_b;

  if(both_ab != 0){
    if(end_a == 0 && start_b == 0) ans--;
  }

  printf("%d\n", ans);

  return 0;
}