#include<iostream>
#include<vector>
#include<map>
#include<algorithm>
#define ll long long
#define mod 1000000007

using namespace std;

int main(){
  ll n,p;
  cin >> n >> p;
  vector<ll> dp(n+1);
  dp[1] = 0;dp[2] = 1;
  for(int i=3;i < n+1;i++) dp[i] = p*dp[i-1]%mod + dp[i-2]%mod;
  ll ans = 0;
  ll sum = 0;
  for(int i=1;i <= n;i++){
    sum += dp[i];
    sum %= mod;
    ans += sum*dp[i] % mod;
    ans = (ans+mod)%mod;
  }
  cout << ans << endl;
  return 0;
}