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:
    nowt += x - nowp
    nowp = x
    if nowt % (2 * t) > t or (nowt + w) % (2 * t) > t:
        nowt = - (-nowt // (2 * t)) * (2 * t)
nowt += L - nowp
print(nowt)