N, L = map(int, input().split())
ans, pre = 0, 0
for i in range(N):
    X, W, T = map(int, input().split())
    now = (ans + X - pre) % (2 * T)
    if T - now < W:
        ans += 2 * T - now
    ans += X + W - pre
    pre = X + W
ans += L - pre
print(ans)