N = gets.to_i
P = gets.split.map(&:to_i)
MOD = 998_244_353

pos = Hash.new
P.each_with_index do |v, i|
  pos[v] = i
end

l = Float::INFINITY
r = -Float::INFINITY
ans = 1

0.upto(N - 1) do |x|
  i = pos[x]

  if (l..r).cover?(i)
    ans *= (r - l - x + 1)
    ans %= MOD
  else
    l = i if l > i
    r = i if r < i
  end
end

puts ans