#include using namespace std; typedef pair pii; typedef long long ll; template using V = vector; template using VV = V>; #define pb push_back #define eb emplace_back #define mp make_pair #define fi first #define se second #define rep(i,n) rep2(i,0,n) #define rep2(i,m,n) for(int i=m;i<(n);i++) #define ALL(c) (c).begin(),(c).end() #ifdef LOCAL #define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl #else #define dump(x) true #endif constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n-1); } template void chmin(T& t, const U& u) { if (t > u) t = u; } template void chmax(T& t, const U& u) { if (t < u) t = u; } template ostream& operator<<(ostream& os, const pair& p) { os<<"("< ostream& operator<<(ostream& os, const vector& v) { os<<"{"; rep(i, v.size()) { if (i) os<<","; os< struct ModInt { using uint = unsigned int; using ull = unsigned long long; using M = ModInt; uint v; ModInt(ll _v = 0) { set_norm(_v % MOD + MOD); } M& set_norm(uint _v) { //[0, MOD * 2)->[0, MOD) v = (_v < MOD) ? _v : _v - MOD; return *this; } explicit operator bool() const { return v != 0; } M operator+(const M& a) const { return M().set_norm(v + a.v); } M operator-(const M& a) const { return M().set_norm(v + MOD - a.v); } M operator*(const M& a) const { return M().set_norm(ull(v) * a.v % MOD); } M operator/(const M& a) const { return *this * a.inv(); } M& operator+=(const M& a) { return *this = *this + a; } M& operator-=(const M& a) { return *this = *this - a; } M& operator*=(const M& a) { return *this = *this * a; } M& operator/=(const M& a) { return *this = *this / a; } M operator-() const { return M() - *this; } M& operator++(int) { return *this = *this + 1; } M& operator--(int) { return *this = *this - 1; } M pow(ll n) const { if (n < 0) return inv().pow(-n); M x = *this, res = 1; while (n) { if (n & 1) res *= x; x *= x; n >>= 1; } return res; } M inv() const { ll a = v, b = MOD, p = 1, q = 0, t; while (b != 0) { t = a / b; swap(a -= t * b, b); swap(p -= t * q, q); } return M(p); } bool operator==(const M& a) const { return v == a.v; } bool operator!=(const M& a) const { return v != a.v; } friend ostream& operator<<(ostream& os, const M& a) { return os << a.v; } static int get_mod() { return MOD; } }; using Mint = ModInt<1000000007>; int main() { int N; cin >> N; int _p; cin >> _p; Mint p(_p); if (N == 1) { puts("0"); return 0; } Mint sum = 0; Mint ans = 0; Mint a = 0, b = 1; sum = 1; ans = 1; for (int i = 3; i <= N; ++i) { Mint c = b * p + a; sum += c; ans += sum * c; a = b; b = c; } cout << ans << endl; return 0; }