def factorial(number)
  if number.zero?
    1
  else
    number * factorial(number - 1)
  end
end

N = gets
N.strip!
map = Hash.new
map.default = 0
begin
N.to_i.times do 
  s = gets
  map[s.strip.chars.sort.join] += 1
end
ans = 0

  map.each_value{|v|
    if v >= 2 then
      ans += factorial(v)/factorial(v-2)/2
    end
  }
rescue
  p 0
end
p ans

