n, l = map(int, input().split())
crosswalks = [tuple(map(int, input().split())) for _ in range(n)]

current_time = 0
prev_pos = 0

for x, w, t in crosswalks:
    distance_to_x = x - prev_pos
    current_time += distance_to_x
    prev_pos = x

    s = t - w
    cycle = 2 * t
    k = current_time // cycle
    if current_time <= k * cycle + s:
        start = current_time
    else:
        k += 1
        start = k * cycle

    current_time = start + w
    prev_pos += w

current_time += l - prev_pos

print(current_time)