def main():
    import sys
    input = sys.stdin.readline

    N, p = map(int, input().split())
    mod = 1000000007

    if N == 1:
        print(0)
        exit()

    A = [0] * N
    A[1] = 1
    S = [0] * N
    S[1] = 1
    for i in range(2, N):
        A[i] = ((p*A[i-1])%mod + A[i-2])%mod
        S[i] = S[i-1] + A[i]
    ans = 0
    for i in range(N):
        ans = (ans + (A[i] * S[i])%mod)%mod
    print(ans)


if __name__ == '__main__':
    main()