#include <bits/stdc++.h>
using namespace std;

template <unsigned Mod> struct Modular {
  using M = Modular;
  unsigned v;
  Modular(long long a = 0) : v((a %= Mod) < 0 ? a + Mod : a) {}
  M operator-() const { return M() -= *this; }
  M& operator+=(M r) { if ((v += r.v) >= Mod) v -= Mod; return *this; }
  M& operator-=(M r) { if ((v += Mod - r.v) >= Mod) v -= Mod; return *this; }
  M& operator*=(M r) { v = (uint64_t)v * r.v % Mod; return *this; }
  M& operator/=(M r) { return *this *= power(r, Mod - 2); }
  friend M operator+(M l, M r) { return l += r; }
  friend M operator-(M l, M r) { return l -= r; }
  friend M operator*(M l, M r) { return l *= r; }
  friend M operator/(M l, M r) { return l /= r; }
  friend bool operator==(M l, M r) { return l.v == r.v; }
};

constexpr long long mod = 1e9 + 7;
using Mint = Modular<mod>;

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int n, p;
  cin >> n >> p;
  vector<Mint> a(n);
  for (int i = 0; i < n; ++i) {
    if (i < 2) {
      a[i] = i;
    } else {
      a[i] = p * a[i - 1] + a[i - 2];
    }
  }
  Mint res, sum;
  for (int i = 0; i < n; ++i) {
    sum += a[i];
    res += sum * a[i];
  }
  cout << res.v << '\n';
}