#pragma region Macros
#include <bits/stdc++.h>
#define rep(i, n) for(int(i) = 0; (i) < (n); (i)++)
#define rrep(i, n) for(int(i) = (n)-1; (i) >= 0; (i)--)
#define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++)
#define ROF(i, m, n) for(int(i) = (n)-1; (i) >= (m); (i)--)
#define ALL(v) (v).begin(), (v).end()
#define LLA(v) (v).rbegin(), (v).rend()
#define SZ(v) (int)(v).size()
#define INT(...)     \
    int __VA_ARGS__; \
    read(__VA_ARGS__)
#define LL(...)     \
    ll __VA_ARGS__; \
    read(__VA_ARGS__)
#define DOUBLE(...)     \
    double __VA_ARGS__; \
    read(__VA_ARGS__)
#define CHAR(...)     \
    char __VA_ARGS__; \
    read(__VA_ARGS__)
#define STRING(...)     \
    string __VA_ARGS__; \
    read(__VA_ARGS__)
#define VEC(type, name, size) \
    vector<type> name(size);  \
    read(name)
#define VEC2(type, name, height, width)                     \
    vector<vector<type>> name(height, vector<type>(width)); \
    read(name)
#define DVEC(type, name1, name2, size)     \
    vector<type> name1(size), name2(size); \
    read(name1, name2);
#define TVEC(type, name1, name2, name3, size)           \
    vector<type> name1(size), name2(size), name3(size); \
    read(name1, name2, name3);
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const int INF = 1 << 30;
const ll LINF = 1LL << 60;
const int MOD = 1e9 + 7;
const char newl = '\n';
const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
template <class T> inline bool between(T x, T l, T r) { return l <= x && x < r; }
template <class T> inline vector<T> make_vec(size_t a, T val) { return vector<T>(a, val); }
template <class... Ts> inline auto make_vec(size_t a, Ts... ts) { return vector<decltype(make_vec(ts...))>(a, make_vec(ts...)); }
void read() {}
template <class T> inline void read(T &a) { cin >> a; }
template <class T, class S> inline void read(pair<T, S> &p) { read(p.first), read(p.second); }
template <class T> inline void read(vector<T> &v) {
    for(auto &&a : v) read(a);
}
template <class T, class U> inline void read(vector<T> &a, vector<U> &b) {
    for(int i = 0; i < a.size(); i++) {
        read(a[i]);
        read(b[i]);
    }
}
template <class T, class U, class V> inline void read(vector<T> &a, vector<U> &b, vector<V> &c) {
    for(int i = 0; i < a.size(); i++) {
        read(a[i]);
        read(b[i]);
        read(c[i]);
    }
}
template <class Head, class... Tail> inline void read(Head &head, Tail &...tail) { read(head), read(tail...); }
template <class T> void write(const T &a) { cout << a << '\n'; }
template <class T> void write(const vector<T> &a) {
    for(int i = 0; i < a.size(); i++) cout << a[i] << (i + 1 == a.size() ? '\n' : ' ');
}
template <class Head, class... Tail> void write(const Head &head, const Tail &...tail) {
    cout << head << ' ';
    write(tail...);
}
template <class T> void writel(const T &a) { cout << a << '\n'; }
template <class T> void writel(const vector<T> &a) {
    for(int i = 0; i < a.size(); i++) cout << a[i] << '\n';
}
template <class Head, class... Tail> void writel(const Head &head, const Tail &...tail) {
    cout << head << '\n';
    write(tail...);
}
template <class T> auto sum(const vector<T> &a) { return accumulate(ALL(a), T(0)); }
template <class T> auto min(const vector<T> &a) { return *min_element(ALL(a)); }
template <class T> auto max(const vector<T> &a) { return *max_element(ALL(a)); }
template <class T, class U> void msort(vector<T> &a, vector<U> &b) {
    assert(a.size() == b.size());
    vector<pair<T, U>> ab(a.size());
    for(int i = 0; i < a.size(); i++) ab[i] = {a[i], b[i]};
    sort(ALL(ab));
    for(int i = 0; i < a.size(); i++) {
        a[i] = ab[i].first;
        b[i] = ab[i].second;
    }
}
template <class T, class U, class V> void msort(vector<T> &a, vector<U> &b, vector<V> &c) {
    assert(a.size() == b.size() && b.size() == c.size());
    vector<tuple<T, U, V>> abc(a.size());
    for(int i = 0; i < a.size(); i++) abc[i] = {a[i], b[i], c[i]};
    sort(ALL(abc));
    for(int i = 0; i < a.size(); i++) {
        a[i] = get<0>(abc[i]);
        b[i] = get<1>(abc[i]);
        c[i] = get<2>(abc[i]);
    }
}
template <class T, class U> inline bool chmax(T &a, U b) {
    if(a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T, class U> inline bool chmin(T &a, U b) {
    if(a > b) {
        a = b;
        return 1;
    }
    return 0;
}
inline int bsf(int v) { return __builtin_ctz(v); } // 最下位の1が下から何番目か
inline int bsf(ll v) { return __builtin_ctzll(v); }
inline int bsr(int v) { return 31 - __builtin_clz(v); } // 最上位の1が下から何番目か
inline int bsr(ll v) { return 63 - __builtin_clzll(v); }
inline int lsb(int v) { return v & -v; } // 最上位の1だけ残す
inline ll lsb(ll v) { return v & -v; }
inline int msb(int v) { return 1 << bsr(v); } // 最上位の1だけ残す
inline ll msb(ll v) { return 1LL << bsr(v); }
struct IO {
    IO() {
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
        cout << fixed << setprecision(10);
    }
} io;
#pragma endregion

/* ModInt */
template <uint_fast64_t MOD> class ModInt {
    using u64 = uint_fast64_t;

  public:
    u64 val;

    ModInt(const u64 x = 0) : val((x + MOD) % MOD) {}
    constexpr u64 &value() { return val; }
    static const u64 get_mod() { return MOD; }
    constexpr ModInt operator-() { return val ? MOD - val : 0; }
    constexpr ModInt operator+(const ModInt &rhs) const {
        return ModInt(*this) += rhs;
    }
    constexpr ModInt operator-(const ModInt &rhs) const {
        return ModInt(*this) -= rhs;
    }
    constexpr ModInt operator*(const ModInt &rhs) const {
        return ModInt(*this) *= rhs;
    }
    constexpr ModInt operator/(const ModInt &rhs) const {
        return ModInt(*this) /= rhs;
    }
    constexpr ModInt &operator+=(const ModInt &rhs) {
        val += rhs.val;
        if(val >= MOD) {
            val -= MOD;
        }
        return *this;
    }
    constexpr ModInt &operator-=(const ModInt &rhs) {
        if(val < rhs.val) {
            val += MOD;
        }
        val -= rhs.val;
        return *this;
    }
    constexpr ModInt &operator*=(const ModInt &rhs) {
        val = val * rhs.val % MOD;
        return *this;
    }

    constexpr ModInt &operator/=(const ModInt &rhs) {
        *this *= rhs.inv();
        return *this;
    }

    constexpr bool operator==(const ModInt &rhs) {
        return this->val == rhs.val;
    }
    constexpr bool operator!=(const ModInt &rhs) {
        return this->val != rhs.val;
    }
    friend constexpr ostream &operator<<(ostream &os, const ModInt<MOD> &x) {
        return os << x.val;
    }
    friend constexpr istream &operator>>(istream &is, ModInt<MOD> &x) {
        return is >> x.val;
    }

    constexpr ModInt inv() const { return ModInt(*this).pow(MOD - 2); }

    constexpr ModInt pow(long long e) const {
        u64 x = 1, p = val;
        while(e > 0) {
            if(e % 2 == 0) {
                p = (p * p) % MOD;
                e /= 2;
            } else {
                x = (x * p) % MOD;
                e--;
            }
        }
        return ModInt(x);
    }
};

using mint = ModInt<MOD>;

int main() {
    INT(n, k);
    write((mint(n).pow(k) - (mint(n - 1)).pow(k)) * n);
}