MOD = 10 ** 9 + 7

n, p = map(int, input().split())
if n == 1:
    print(0)
    exit()
dp = [0, 1]
for _ in range(n - 2):
    x = p * dp[-1] + dp[-2]
    dp.append(x % MOD)
    
tot = sum(dp)
ans = tot * tot + sum(d ** 2 for d in dp)
ans %= MOD
print(ans * pow(2, MOD - 2, MOD) % MOD)