require "big"

struct Int
  def pow(n : Int, mod = nil ) : Int
    a = to_i64
    res = 1_i64
    while n > 0
      if (n & 1) != 0
        res *= a
        res %= mod if mod
      end
      a *= a
      a %= mod if mod
      n >>= 1
    end
    res
  end
end

mod = 998244353i64

n, k = gets.to_s.split.map{ |e| e.to_big_i }
a    = gets.to_s.split.map{ |e| e.to_big_i }

puts a.sum * 2.to_big_i.pow(k, mod) % mod