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 Python (3.4.3) (judge verdict: Accepted)

#!/usr/bin/env python3
import sys


def solve(N: int, s: "List[str]"):
    x = 0
    a = 0
    b = 0
    for i in s:
        if(i[0] == 'B' and i[-1] == 'A'):
            x += 1
        elif(i[-1] == 'A'):
            a += 1
        elif(i[0] == 'B'):
            b += 1

    # ans1 = max(0,x-1) + (min(a,b) if a==b else min(a,b)+1)    
    
    if(x == 0):
        ans1 = min(a,b)
    else:
        ans1 = max(0,x-1)+min(a,b)
        if(a > 0 or b > 0):
            ans1 += 1

    
    # ans1 = max(0,x-1) 
    # if(a == b):
    #     ans1 += min(a,b)
    # else:
    #     if(x == 0):
    #         ans1 += min(a,b)
    #     else:
    #         ans1 += min(a,b)+1 
    

    ans2 = 0
    for i in s:
        ans2 += i.count('AB')

    print(ans1+ans2)
    
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    s = [ next(tokens) for _ in range(N) ]  # type: "List[str]"
    solve(N, s)

if __name__ == '__main__':
    main()