n,p = map(int,input().split())
mod = 10**9+7

a = [0]*(n)
a[0] = 0
a[1] = 1

for i in range(2,n):
    a[i] = p*a[i-1]+a[i-2]
    a[i] %= mod

rui = [0]*(n+1)
for i in range(n):
    rui[i+1] = rui[i]+a[i]
    rui[i+1] %= mod

ans = 0

for i in range(n):
    ans += a[i]*(rui[i+1]-rui[0]+mod)%mod
    ans %= mod
print(ans)