n, m = gets.split.map(&:to_i)
ranks = gets.split.map(&:to_i)
classes = []
ranks.each do |i|
  if i % m == 0
    s = i / m - 1
    a = m
  else
    s = i / m
    a = i % m
  end
  classes << if s.even?
               a
             else
               m + 1 - a
             end
end
puts classes[0] == classes[1] ? 'YES' : 'NO'