#include <iostream>
#include <vector>
#include <cmath>
#include <iomanip>
#include <algorithm>
using namespace std;

// chmax, chmin
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

// debug stream of pair, vector 
#define COUT(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << endl
template<class T1, class T2> ostream& operator << (ostream &s, pair<T1,T2> P)
{ return s << '<' << P.first << ", " << P.second << '>'; }
template<class T> ostream& operator << (ostream &s, vector<T> P)
{ for (int i = 0; i < P.size(); ++i) { if (i > 0) { s << " "; } s << P[i]; } return s; }


// modint
template<int MODULO> struct Fp {
    long long val;

    constexpr Fp(long long v = 0) noexcept : val(v % MODULO) {
        if (val < 0) v += MODULO;
    }
    constexpr Fp operator - () const noexcept {
        return val ? MODULO - val : 0;
    }
    constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; }
    constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; }
    constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; }
    constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; }
    constexpr Fp& operator += (const Fp& r) noexcept {
        val += r.val;
        if (val >= MODULO) val -= MODULO;
        return *this;
    }
    constexpr Fp& operator -= (const Fp& r) noexcept {
        val -= r.val;
        if (val < 0) val += MODULO;
        return *this;
    }
    constexpr Fp& operator *= (const Fp& r) noexcept {
        val = val * r.val % MODULO;
        return *this;
    }
    constexpr Fp& operator /= (const Fp& r) noexcept {
        long long a = r.val, b = MODULO, u = 1, v = 0;
        while (b) {
            long long t = a / b;
            a -= t * b; swap(a, b);
            u -= t * v; swap(u, v);
        }
        val = val * u % MODULO;
        if (val < 0) val += MODULO;
        return *this;
    }
    constexpr bool operator == (const Fp& r) const noexcept {
        return this->val == r.val;
    }
    constexpr bool operator != (const Fp& r) const noexcept {
        return this->val != r.val;
    }
};

template<int MODULO> constexpr ostream& operator <<
(ostream &os, const Fp<MODULO>& x) noexcept {
    return os << x.val;
}
template<int MODULO> constexpr istream& operator >>
(istream &is, Fp<MODULO>& x) noexcept {
    return is >> x.val;
}

template<int MODULO> constexpr Fp<MODULO> modpow
(const Fp<MODULO> &a, long long n) noexcept {
    if (n == 0) return 1;
    auto t = modpow(a, n / 2);
    t = t * t;
    if (n & 1) t = t * a;
    return t;
}


template<int MODULO> struct BiCoef {
    vector<Fp<MODULO> > fac, inv, finv;
    constexpr BiCoef(int n = 210000) noexcept : fac(n, 1), inv(n, 1), finv(n, 1) {
        for(int i = 2; i < n; i++){
            fac[i] = fac[i-1] * i;
            inv[i] = -inv[MODULO%i] * (MODULO/i);
            finv[i] = finv[i-1] * inv[i];
        }
    }
    constexpr Fp<MODULO> com(int n, int k) const noexcept {
        if (n < k || n < 0 || k < 0) return 0;
        return fac[n] * finv[k] * finv[n-k];
    }
};


const int MAX = 201010;
const int MOD = 1000000007;
using mint = Fp<MOD>;


int main() {
    BiCoef<MOD> bc(MAX);

    int N, K;
    cin >> N >> K;
    mint res = 0;
    for (int i = 0; i <= K; ++i) {
        mint tmp = bc.com(K, i) * modpow(mint(i), N);
        if ( (K-i) & 1 ) res -= tmp;
        else res += tmp;
    }
    cout << res << endl;
}