n, l = map(int, input().split())
c = 0
ans = 0
for _ in range(n):
    x, w, t = map(int, input().split())
    ans += x - c
    q, r = divmod(ans, t)
    if q % 2 == 0:
        if r + w <= t:
            ans += w
        else:
            ans += w + t + (t - r)
    else:
        ans += t - r + w
    c = x + w
ans += l - c
print(ans)