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)


def main():
    buf = input()
    N = int(buf)
    s = []
    for i in range(N):
        buf = input()
        s.append(buf)
    ab_count = 0
    for i in range(N):
        for j in range(len(s[i])-1):
            if s[i][j] == 'A' and s[i][j+1] == 'B':
                ab_count += 1
    A_count = 0
    B_count = 0
    BA_count = 0
    for i in range(N):
        if s[i][-1] == 'A' and s[i][0] == 'B':
            BA_count += 1
        elif s[i][-1] == 'A':
            A_count += 1
        elif s[i][0] == 'B':
            B_count += 1
    # BA-BA
    ab_count += max(0, BA_count - 1)
    # A-BA-B
    if BA_count > 0 and A_count > 0:
        A_count -= 1
        ab_count += 1
    if BA_count > 0 and B_count > 0:
        B_count -= 1
        ab_count += 1
    # A-B
    ab_count += min(B_count, A_count)
    print(ab_count)


if __name__ == '__main__':
    main()