#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
typedef long long ll;
typedef pair<int,int> pp;
const int INF = 1e9;
const int MOD = 1000000007;

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