N, M = map(int, input().split())

class facmod:
    def __init__(self, N: int, md: int) -> None:
        assert N < md
        self.md = md
        self.facs = [1] * (N + 1)
        self.facinvs = [1] * (N + 1)
        for i in range(1, N + 1):
            self.facs[i] = self.facs[i - 1] * i % md
        self.facinvs[N] = pow(self.facs[i], md - 2, md)
        for i in range(N - 1, 0, -1):
            self.facinvs[i] = self.facinvs[i + 1] * (i + 1) % md

    def nCr(self, n: int, r: int) -> int:
        if n < 0 or r < 0 or n < r:
            return 0
        return (self.facs[n] * self.facinvs[r]) % md * self.facinvs[n - r] % md


md = 1000000007
fac = facmod(1000000, md)

ncrs = [fac.nCr(N, i) for i in range(N + 1)]
ncr_cums = [0] * (N + 2)
for i in range(N + 1):
    ncr_cums[i + 1] = ncr_cums[i] + ncrs[i]
    if ncr_cums[i + 1] >= md:
        ncr_cums[i + 1] -= md

ret = 0

def add_closed(l: int, r: int) -> None:
    global ret
    if l > r:
        return
    ret += ncr_cums[(r if r < N else N) + 1] - ncr_cums[l if l >= 0 else 0]


for h in range(1, N + 1):
    if M - (N - M) >= h:
        add_closed(M, N)
    else:
        l = h + (N - h + 1) // 2
        add_closed(l, N)
        add_closed(l + 1 - ((N - h) & 1), l + l - M - ((N - h) & 1))

K = N - M
for h in range(1, K + 1):
    l = h + (N - h + 1) // 2
    if l <= K:
        add_closed(l, K)
        add_closed(l + 1 - ((N - h) & 1), N)
    else:
        add_closed(h + N - K, N)

for i in range(M, N + 1):
    ret += fac.nCr(N, i) * N

print(ret % md)