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 Go (1.6) (judge verdict: Accepted)

package main

import "fmt"

func min(x, y int) int {
	if x < y {
		return x
	}
	return y
}

func main() {
	var (
		n int
		s string
	)
	fmt.Scan(&n)
	count, bxa, bx, xa := 0, 0, 0, 0
	for i := 0; i < n; i++ {
		fmt.Scan(&s)
		for j := 0; j < len(s)-1; j++ {
			if s[j] == 'A' && s[j+1] == 'B' {
				count++
			}
		}
		if s[0] == 'B' && s[len(s)-1] == 'A' {
			bxa++
		} else if s[0] == 'B' {
			bx++
		} else if s[len(s)-1] == 'A' {
			xa++
		}
	}

	if bxa == 0 {
		count += min(bx, xa)
	} else if bx == 0 && xa == 0 {
		count += bxa - 1
	} else {
		count += bxa + min(bx, xa)
	}
	fmt.Println(count)
}