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

mod = 10**9+7
A = [0]*(N+1)
B = [0]*(N+1)
A[1] = 1
B[1] = 1
for i in range(2, N):
    A[i] = (p*A[i-1] + A[i-2]) % mod
    B[i] = (B[i-1] + A[i]) % mod

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

print(ans)