local n, l = io.read("*n", "*n")
local curpos, curtime = 0, 0
for i = 1, n do
  local x, w, t = io.read("*n", "*n", "*n")
  curtime = curtime + x - curpos
  curpos = x
  local rem = curtime % (2 * t)
  if t - w < rem then
    curtime = curtime + 2 * t - rem
  end
  curpos = curpos + w
  curtime = curtime + w
end
print(curtime + l - curpos)