#include using namespace std; // Define using ll = long long; using ull = unsigned long long; using ld = long double; template using pvector = vector>; template using rpriority_queue = priority_queue, greater>; constexpr const ll dx[4] = {1, 0, -1, 0}; constexpr const ll dy[4] = {0, 1, 0, -1}; constexpr const ll MOD = 1e9 + 7; constexpr const ll mod = 998244353; constexpr const ll INF = 1LL << 60; constexpr const ll inf = 1 << 30; constexpr const char rt = '\n'; constexpr const char sp = ' '; #define mp make_pair #define mt make_tuple #define pb push_back #define eb emplace_back #define elif else if #define all(a, v, ...) \ ([&](decltype((v)) w) { return (a)(begin(w), end(w), ##__VA_ARGS__); })(v) #define rall(a, v, ...) \ ([&](decltype((v)) w) { return (a)(rbegin(w), rend(w), ##__VA_ARGS__); })(v) #define fi first #define se second template bool chmax(T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; } template bool chmin(T &a, const T &b) { if (a > b) { a = b; return 1; } return 0; } // Debug #define debug(...) \ { \ cerr << __LINE__ << ": " << #__VA_ARGS__ << " = "; \ for (auto &&X : {__VA_ARGS__}) cerr << "[" << X << "] "; \ cerr << rt; \ } #define dump(a, h, w) \ { \ cerr << __LINE__ << ": " << #a << " = [" << rt; \ rep(_i, h) { \ rep(_j, w) cerr << a[_i][_j] << sp; \ cerr << rt; \ } \ cerr << "]" << rt; \ } #define vdump(a, n) \ { \ cerr << __LINE__ << ": " << #a << " = ["; \ rep(_i, n) if (_i) cerr << sp << a[_i]; \ else cerr << a[_i]; \ cerr << "]" << rt; \ } // Loop #define inc(i, a, n) for (ll i = (a), _##i = (n); i <= _##i; ++i) #define dec(i, a, n) for (ll i = (a), _##i = (n); i >= _##i; --i) #define rep(i, n) for (ll i = 0, _##i = (n); i < _##i; ++i) #define each(i, a) for (auto &&i : a) // Stream #define fout(n) cout << fixed << setprecision(n) struct io { io() { cin.tie(nullptr), ios::sync_with_stdio(false); } } io; // Speed #pragma GCC optimize("Ofast") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") // Math inline constexpr ll gcd(const ll a, const ll b) { return b ? gcd(b, a % b) : a; } inline constexpr ll lcm(const ll a, const ll b) { return a / gcd(a, b) * b; } inline constexpr ll modulo(const ll n, const ll m = MOD) { ll k = n % m; return k + m * (k < 0); } inline constexpr ll chmod(ll &n, const ll m = MOD) { n %= m; return n += m * (n < 0); } inline constexpr ll mpow(ll a, ll n, const ll m = MOD) { ll r = 1; rep(i, 64) { if (n & (1LL << i)) r *= a; chmod(r, m); a *= a; chmod(a, m); } return r; } inline ll inv(const ll n, const ll m = MOD) { ll a = n, b = m, x = 1, y = 0; while (b) { ll t = a / b; a -= t * b; swap(a, b); x -= t * y; swap(x, y); } return modulo(x, m); } signed main() { ll P, K; cin >> P >> K; ll cnt[K + 1][2]; rep(i, K + 1) rep(j, 2) cnt[i][j] = 0; cnt[0][0] = 1; rep(i, K) { cnt[i + 1][1] = (cnt[i][0] * (P - 1) + cnt[i][1] * (2 * P - 2)) % MOD; cnt[i + 1][0] = (cnt[i][0] * (P + 1) + cnt[i][1] * 2) % MOD; } cout << cnt[K][0] << rt; } // -g -D_GLIBCXX_DEBUG -fsanitize=undefined