n, p = map(int,input().split())
MOD = 10**9+7
a = [0, 1]
for i in range(n-2):
    a.append((a[i+1]*p+a[i])%MOD)
s = 0
for i in range(len(a)):
    s += pow(a[i], 2, MOD)
    s %= MOD
ans = (pow(sum(a), 2, MOD)+s)*pow(2, MOD-2, MOD)
ans %= MOD
print(ans)