# util functions

# debug
$debugFlag = ( ARGV[0] != nil )
p "==== DEBUG MODE ====" if $debugFlag

def pd(str)
  p str if $debugFlag
end

# input
lc = 0
aonly = 0
bonly = 0
abboth = 0
intab = 0
while l = $stdin.gets do
  if lc == 0
  else
    input = l.chomp
    intab += input.scan("AB").length
    if input[0..0] == "B"
      if input[-1..-1] == "A"
        abboth += 1
      else
        bonly += 1
      end
    elsif input[-1..-1] == "A"
      aonly += 1
    end
  end
  lc += 1
end

print "abboth:" if $debugFlag
pd abboth
print "aonly:" if $debugFlag
pd aonly
print "bonly:" if $debugFlag
pd bonly
print "intab:" if $debugFlag
pd intab

# body

min = [aonly, bonly].min
max = [aonly, bonly].max

delta = 0
if abboth - [(max - min), abboth].min > 0
  delta = (abboth - [(max - min), abboth].min)
  if max == min
    delta -= 1
  end
end

puts intab + min + [(max - min), abboth].min + delta