N = gets.to_i
A = gets.split.map(&:to_i).sort
ptn_cnt = 1

until A.empty?
  v = A.shift
  cnt = 1

  while A.size > 0 && v == A.first
    A.shift
    cnt += 1
  end

  ptn_cnt *= (1..cnt).inject(:*)
end

puts Rational(1, Rational(ptn_cnt, (1..N).inject(:*))).to_i