N, p = map(int, input().split())
a = [0, 1]
mod = 10**9+7
if N < 3:
    res = 0
    for i in range(N):
        for j in range(i+1):
            res += a[i]*a[j]
    print(res)
else:
    ss = 1
    sm = 1
    for i in range(2, N):
        n = p*a[-1]+a[-2]
        n %= mod
        ss += n**2
        ss %= mod
        sm += n
        sm %= mod
        a.append(n)
    print(((sm**2-ss)//2+ss)%mod)