#include <bits/stdc++.h>

using namespace std;

#define lli long long int
#define REP(i,s,n) for(int i=s;i<n;i++)
#define MOD 1000000007
#define NUM 2520
#define INF (1LL<<50)
#define DEBUG 0
#define mp(a,b) make_pair(a,b)
#define SORT(V) sort(V.begin(),V.end())
#define PI (3.141592653589794)

lli a[1001000];
lli sum[1001000];

signed main(){

	lli n,p;

	cin>>n>>p;

	a[0]=0;
	sum[0]=0;
	a[1]=1;
	sum[1]=1;

	REP(i,2,1001000){
		a[i]=(p*a[i-1]+a[i-2])%MOD;
		sum[i] = (sum[i-1]+a[i])%MOD;
	}

	lli ans=0;
	REP(i,0,n){
		ans += (a[i]*sum[i])%MOD;
		ans%=MOD;
	}
	cout<<ans<<endl;

	return 0;
}