import java.util.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int p = sc.nextInt();
        long[] fibo = new long[n];
        if (n > 1) {
            fibo[1] = 1;
        }
        long[] sums = new long[n];
        sums[1] = 1;
        for (int i = 2; i < n; i++) {
            fibo[i] = (p * fibo[i - 1] + fibo[i - 2]) % MOD;
            sums[i] = (sums[i - 1] + fibo[i]) % MOD;
        }
        long ans = 0;
        for (int i = 1; i < n; i++) {
            ans += fibo[i] * ((sums[n - 1] - sums[i - 1] + MOD) % MOD) % MOD;
            ans %= MOD;
        }
        System.out.println(ans);
    }
}