// I SELL YOU...! 
#include<iostream>
#include<vector>
#include<algorithm>
#include<functional>
#include<queue>
#include<chrono>
#include<iomanip>
#include<map>
#include<set>
#define MOD 1000000007
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
void init_io(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << setprecision(10);
}
signed main(){
  init_io();
  ll n,p,ans=0;
  cin >> n >> p;
  vector<ll> a(n+1),sum(n+2);
  a[0] = 0;
  a[1] = 1;
  sum[0] = 0;
  sum[1] = 1;
  for(int i=2;i<=n;i++){
    a[i] = p*a[i-1] + a[i-2];
    a[i] %= MOD;
    sum[i] = sum[i-1] + a[i];
    sum[i] %= MOD;
  }
  for(int i=n-1;i>=0;i--){
    ans += (sum[i]*a[i])%MOD;
    ans %= MOD;
  }
  cout << ans << endl;
}