class Yukicoder
  def initialize
    n, k = gets.chomp.split.map(&:to_i)
    s = gets.chomp

    list = Array.new(n, 0)
    buy_count = 0
    atari_cost = 0

    s.chars.each_with_index do |ch, index|
      if atari_cost > 0
        atari_cost -= 1
      else
        buy_count += 1
      end

      list[index] = buy_count

      if ch == '1'
        atari_cost += 1
      elsif ch == '2'
        atari_cost += 2
      end
    end

    if n >= k
      puts list[k-1]
    else
      x = k / n - 1

      if k % n == 0
        y = [buy_count, atari_cost].map{|i| i * (x+1)}
        if y[1] > 0
          puts [y[0] - y[1] + 1, 1].max
        else
          puts [y[0] - y[1], 1].max
        end
      else
        y = [buy_count, atari_cost].map{|i| i * x}
        puts [buy_count + x * (buy_count - atari_cost) + [list[k%n-1] - atari_cost, 0].max, buy_count].max
      end
    end

  end
end

Yukicoder.new