def Pashka_lublu_tebya(n):
    Pashenka = [0] * n
    if n == 0:
        return(1)
    else:
        Pashenka[0] = 2
        if n > 1:
            Pashenka[1] = 7
            if n > 2:
                Pashenka[2] = 22
                if n > 3:
                    for i in range(3, n):
                        Pashenka[i] = (Pashenka[i - 1] - Pashenka[i - 3] + 2 * Pashenka[i - 1] + Pashenka[i - 2])  % (10 ** 9 + 7)
        return Pashenka[n - 1]





n, k = map(int, input().split())
if k == 0:
    print(Pashka_lublu_tebya(n))