N, L = map(int, input().split())
XWT = [list(map(int, input().split())) for _ in range(N)]
nowt = 0
nowp = 0
for x, w, t in XWT:
    t2 = t * 2
    nowt += x - nowp
    nowp = x
    if nowt % t2 <= t and (nowt + w) % t2 <= t and nowt // t2 == (nowt + w) // t2:
        continue
    else:
        nowt = - (-nowt // (2 * t)) * (2 * t)
nowt += L - nowp
print(nowt)