#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    ll n, p;
    cin >> n >> p;
    ll MOD = 1e9+7;

    ll a[n + 10];
    a[0] = 0;
    a[1] = 1;
    srep(i,2,n){
        a[i] = p*a[i-1] + a[i-2];
        a[i] %= MOD;
    }

    ll ans = 0;
    ll sum = 0;
    rep(i,n){
        sum = (sum + a[i]) % MOD;
        ans += a[i] * sum;
        ans %= MOD;
    }

    cout << ans << endl;
    return 0;
}