#include <algorithm>
#include <bitset>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#define MOD (1000000007l)
#define ll long long
#define rep(i, n) for (ll i = 0; i < (n); i++)

using namespace std;

void solve() {
  ll N, P;
  cin >> N >> P;
  vector<ll> A(N);
  A[0] = 0;
  A[1] = 1;
  for (ll i = 2; i < N; i++) {
    ll tmp = P * A[i-1] + A[i-2];
    tmp %= MOD;
    A[i] = tmp;
  }
  vector<ll> B(N);
  for (ll i = 1; i < N; i++) {
    B[i] = (B[i-1] + A[i]) % MOD;
  }

  ll ans = 0;
  rep (i, N) {
    ans += B[i] * A[i];
    ans %= MOD;
  }

  cout << ans << endl;
}

int main(void) {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout.precision(12);
  cout << fixed;
  solve();
  return 0;
}