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"
	"strings"
)

func main() {
	var n int
	fmt.Scan(&n)

	s := make([]string, n)
	for i := 0; i < n; i++ {
		fmt.Scan(&s[i])
	}

	ans := 0
	hb := 0
	ta := 0
	hbta := 0
	for _, v := range s {
		c := strings.Count(v, "AB")
		if c > 0 {
			strings.Replace(v, "AB", "", c)
			ans += c
		}
		if strings.HasPrefix(v, "B") && strings.HasSuffix(v, "A") {
			hbta++
			continue
		}
		if strings.HasPrefix(v, "B") {
			hb++
		}
		if strings.HasSuffix(v, "A") {
			ta++
		}
	}
	if hbta == 0 {
		if hb < ta {
			ans += hb
		} else {
			ans += ta
		}
	} else {
		if hb+ta == 0 {
			ans += hbta - 1
		} else {
			ans += hbta
			if hb < ta {
				ans += hb
			} else {
				ans += ta
			}
		}
	}
	fmt.Println(ans)
}