def combi(n,k)
  sum = 1
  (n-k).times do|i|
    sum = sum*(i + k+1)
  end
  return sum
end

def arr_comp(a,b)
  a.length.times do|i|
    if(a[i] != b[i])
      return false;
    end
  end
  return true;
end

n = gets.chomp.to_i
s = []
n.times do
  s << gets.chomp
end

hash = {"a"=>0, "b"=>1, "c"=>2, "d"=>3, "e"=>4, "f"=>5, "g"=>6, "h"=>7, "i"=>8, "j"=>9, "k"=>10, "l"=>11, "m"=>12, "n"=>13, "o"=>14, "p"=>15, "q"=>16, "r"=>17, "s"=>18, "t"=>19, "u"=>20, "v"=>21, "w"=>22, "x"=>23, "y"=>24, "z"=>25}

hash_arr = []
count_arr = []

n.times do|i|
  #a = hash.dup
  a = Array.new(26, 0)
  s[i].each_char do|c|
    a[hash[c]] += 1
  end
  #puts "now a = #{a}"
  flag = 1
  (hash_arr.length).times do |j|
    if( arr_comp(hash_arr[j],a) ) then
      flag = 0
      count_arr[j] += 1
      break
    end
  end
  if(flag == 1) then
    hash_arr << a
    count_arr << 0
  end
end

#puts "count_arr = #{count_arr}"
sum = 0
count_arr.each do|el|
  if(el != 0) then
    sum += combi( (el+1), 2)
  end
end
puts sum