mod = 10 ** 9 + 7

N, p = map(int, input().split())
A = [0, 1]
for i in range(N - 2):
    v = p * A[-1] + A[-2]
    A.append(v % mod)

ans = 0
Acum = 0
for i in range(N):
    a = A[i]
    ans = (ans + a * a) % mod
    Acum = (Acum + a) % mod

ans = (ans + Acum * Acum) % mod
ans = ans * pow(2, mod - 2, mod) % mod
print(ans)