N,L = map(int,input().split())
A = [0]+[list(map(int,input().split())) for _ in range(N)]
ans = A[1][0]
for i in range(1,N+1):
    x,w,t = A[i]
    q = ans//(2*t)
    r = ans%(2*t)
    if r>=t or t-r<w:
        ans += 2*t-r
    if i==N:
        ans += L-x
    else:
        ans += A[i+1][0]-x
print(ans)