#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int INF = 1e9;
const ll LINF = 1e18;
template<class S,class T> ostream& operator << (ostream& out,const pair<S,T>& o){ out << "(" << o.first << "," << o.second << ")"; return out; }
template<class T> ostream& operator << (ostream& out,const vector<T>& V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; }
template<class T> ostream& operator << (ostream& out,const vector<vector<T> >& Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; }
template<class S,class T> ostream& operator << (ostream& out,const map<S,T>& mp){ out << "{ "; for(auto it = mp.begin(); it != mp.end(); it++){ out << it->first << ":" << it->second; if(mp.size()-1 != distance(mp.begin(),it)) out << ", "; } out << " }"; return out; }
template<typename T>vector<T> make_v(size_t a){return vector<T>(a);}
template<typename T,typename... Ts>auto make_v(size_t a,Ts... ts){return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));}
template<typename T,typename V> typename enable_if<is_class<T>::value==0>::type fill_v(T &t,const V &v){t=v;}
template<typename T,typename V> typename enable_if<is_class<T>::value!=0>::type fill_v(T &t,const V &v){for(auto &e:t) fill_v(e,v);}
/*
 <url:>
 問題文============================================================
 =================================================================
 解説=============================================================
 ================================================================
 */

constexpr ll MOD = 1e9+7;
template<class Type>
Type solve(Type res = Type()){
    ll N,p; cin >> N >> p;
    ll sumA = 0;
    vector<ll> a(N+1);
    a[1] = 0; a[2] = 1;
    for(int n = 3; n <= N;n++){
        a[n] = p*a[n-1] + a[n-2];
        a[n] %= MOD;
    }
    
    for(int n = 1; n <= N;n++){
        sumA += a[n];
        sumA %=MOD;
        res += a[n] * sumA %MOD;
        res %=MOD;
    }
    return res;
}
int main(void) {
    cin.tie(0); ios::sync_with_stdio(false);
    //solve<ll>(0);
    cout << fixed << setprecision(12) << solve<ll>() << endl;
    return 0;
}