N, p = map(int, input().split())
mod = 10 ** 9 + 7
P = [1] * (N + 1)
for i in range(N):
    P[i + 1] = P[i] * p
    P[i + 1] %= mod
invp = pow(p-1, mod-2, mod)
ans = 0
A = [0] * (N + 1)
A[1] = 1
for i in range(2, N + 1):
    A[i] = p * A[i - 1] + A[i - 2]
    A[i] %= mod
Ac = [0] * (N + 1)
Ac[0] = A[0]
for i in range(1, N + 1):
    Ac[i] = Ac[i - 1] + A[i]
    Ac[i] %= mod        
for i in range(1, N):
    ans += A[i] * Ac[i]
    ans %= mod
print(ans)