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;

using ll =long long;
const ll INFll = 0x7F7F7F7F7F7F7F7F;
const int INFint = 100100100;

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n,flag=0,ans=0, la=0, fb=0;
    cin >> n;
    int ssize=0;
    vector<string> s(n);

    for (int i=0;i<n;i++){
        cin >> s[i];
        ssize=s[i].size();
        for (int j=0;j+1<ssize;j++){
            if (s[i][j]=='A'  && s[i][j+1]=='B') ans++;
        }
        if (s[i][(ssize-1)]=='A') la++;
        if (s[i][0]=='B') fb++;
        if (s[i][(ssize-1)]=='A' && s[i][0]=='B') flag++;
    }
    ans = ans+min(fb, la);
    if (flag > 1) ans--;
    cout << ans << endl;
    return 0;
}