#include<bits/stdc++.h>
using namespace std;
#ifdef LOCAL_DEBUG
  #include "LOCAL_DEBUG.hpp"
#endif
#define int long long
const int MOD = 1e9 + 7;

signed main(){

  int n, p; cin >> n >> p;
  vector<int> dp(n+1);
  dp[1] = 0, dp[2] = 1;
  for(int i = 3; i <= n; i++){
    dp[i] = p * dp[i-1] + dp[i-2];
    dp[i] %= MOD;
  }

  vector<int> imos(n+2, 0);
  for(int i = 0; i <= n; i++){
    imos[i+1] = imos[i] + dp[i];
    imos[i+1] %= MOD;
  }
  
  int ans = 0;
  for(int i = 1; i <= n; i++){
    ans = (ans + dp[i] * imos[i+1]) % MOD;
  }
  cout << ans << endl;

  return 0;
}