def safe?(t,iv)
  t % (iv*2) < iv
end

n,l = gets.split.map(&:to_i)

lx = 0; lt = 0
n.times{
  x,w,t = gets.split.map(&:to_i)

  lt += x-lx
  if !safe?(lt,t) || !safe?(lt+w-1,t)
    lt = (lt+t*2-1)/(t*2)*t*2
  end

  lx = x
}

lt += l-lx

p lt