require 'set'

def solve(ars)
  a = []
  ars.each do |s1|
    brs = ars.dup
    brs.delete(s1)
    brs.each do |s2|
      a << s1 + s2
    end
  end
  Set.new(a).size
end

n = gets.chomp.to_i
ars = Array.new(n){gets.chomp}

puts solve(ars)