#define _GLIBCXX_DEBUG #include using namespace std; #define rep(i,x) for(ll i = 0; i < (ll)(x); i++) #define rrep(i,x) for(ll i = (ll)(x)-1;0 <= i; i--) #define reps(i,x) for(ll i = 1; i < (ll)(x)+1; i++) #define rreps(i,x) for(ll i = (ll)(x); 1 <= i; i--) #define debug(x) cerr << #x << ": " << (x) << "\n"; #define all(x) (x).begin(), (x).end() typedef long long ll; typedef long double ld; typedef pair P; typedef pair Pll; typedef vector vl; typedef vector> vvl; typedef vector>> vvvl; const ll INF = numeric_limits::max()/4; const int n_max = 1e5+10; #define int ll template class modint { using i64 = int_fast64_t; public: i64 a; constexpr modint(const i64 x = 0) noexcept { this -> a = x % Modulus; if(a < 0){ a += Modulus; } } constexpr int getmod() { return Modulus; } constexpr modint operator - () const noexcept { return a ? Modulus - a : 0; } // constexpr i64 &value() const noexcept {return a;} constexpr const i64 &value() const noexcept {return a;} constexpr modint operator+(const modint rhs) const noexcept { return modint(*this) += rhs; } constexpr modint operator-(const modint rhs) const noexcept { return modint(*this) -= rhs; } constexpr modint operator*(const modint rhs) const noexcept { return modint(*this) *= rhs; } constexpr modint operator/(const modint rhs) const noexcept { return modint(*this) /= rhs; } constexpr modint &operator+=(const modint rhs) noexcept { a += rhs.a; if(a >= Modulus) { a -= Modulus; } return *this; } constexpr modint &operator-=(const modint rhs) noexcept { if(a < rhs.a) { a += Modulus; } a -= rhs.a; return *this; } constexpr modint &operator*=(const modint rhs) noexcept { a = a * rhs.a % Modulus; return *this; } constexpr modint &operator/=(modint rhs) noexcept { i64 a_ = rhs.a, b = Modulus, u = 1, v = 0; while(b){ i64 t = a_/b; a_ -= t * b; swap(a_,b); u -= t * v; swap(u,v); } a = a * u % Modulus; if(a < 0) a += Modulus; return *this; } // 自前実装 constexpr bool operator==(const modint rhs) noexcept { return a == rhs.a; } constexpr bool operator!=(const modint rhs) noexcept { return a != rhs.a; } constexpr bool operator>(const modint rhs) noexcept { return a > rhs.a; } constexpr bool operator>=(const modint rhs) noexcept { return a >= rhs.a; } constexpr bool operator<(const modint rhs) noexcept { return a < rhs.a; } constexpr bool operator<=(const modint rhs) noexcept { return a <= rhs.a; } // constexpr modint& operator++() noexcept { // return (*this) += modint(1); // } // constexpr modint operator++(int) { // modint tmp(*this); // operator++(); // return tmp; // } // constexpr modint& operator--() noexcept { // return (*this) -= modint(1); // } // constexpr modint operator--(int) { // modint tmp(*this); // operator--(); // return tmp; // } template friend constexpr modint modpow(const modint &mt, T n) noexcept { if(n < 0){ modint t = (modint(1) / mt); return modpow(t, -n); } modint res = 1, tmp = mt; while(n){ if(n & 1)res *= tmp; tmp *= tmp; n /= 2; } return res; } }; const ll MOD = 1e9+7; using mint = modint; // 標準入出力対応 std::ostream &operator<<(std::ostream &out, const modint &m) { out << m.a; return out; } std::istream &operator>>(std::istream &in, modint &m) { ll a; in >> a; m = mint(a); return in; } void print() { cout << endl; } // template // void print(Head&& head, Tail&&... tail) { // cout << head; // if (sizeof...(tail) != 0) cout << " "; // print(forward(tail)...); // } template void print(vector &vec) { for (auto& a : vec) { cout << a; if (&a != &vec.back()) cout << " "; } cout << endl; } template void print(vector &vec, ll k){ ll n = vec.size(); k = min(k, n); rep(i,k-1)cout << vec[i] << " "; cout << vec[k-1] << endl; } template void print(vector> &df) { for (auto& vec : df) { print(vec); } } template void print(pair &p){ cout << p.first << " " << p.second << "\n"; } signed main(){ cin.tie(nullptr); ios::sync_with_stdio(false); ll p,k; cin >> p >> k; vector F(k+1), G(k+1); F[1] = p+1; G[1] = p-1; reps(i,k-1){ F[i+1] = mint(p+1) * F[i] + mint(2) * G[i]; G[i+1] = mint(p-1) * F[i] + mint(2) * mint(p-1) * G[i]; } // print(F);print(G); cout << F[k] << endl; }