N = gets.to_i
A = gets.split.map(&:to_i)
counter = Hash.new(0)
ans = 0

N.times do |i|
  a = A[i]
  counter[a] += 1

  if a == 1
    ans += 3 * counter[2]
    ans += 2 * (i - counter[2])
  elsif a == 2
    ans += 3 * counter[1]
    ans += (i - counter[1])
  else
    ans += 2 * counter[1]
    ans += (i - counter[1])
  end
end

puts ans