#include<deque>
#include<queue>
#include<vector>
#include<algorithm>
#include<iostream>
#include<set>
#include<cmath>
#include<tuple>
#include<string>
#include<chrono>
#include<functional>
#include<iterator>
#include<random>
#include<unordered_set>
#include<unordered_map>
#include<array>
#include<map>
#include<bitset>
#include<iomanip>
#include<list>
#include <numeric>
using namespace std;
typedef unsigned long long int ulint;
typedef long long int llint;
typedef long double lldo;
#define mp make_pair
#define mt make_tuple
#define pub push_back
#define puf push_front
#define pob pop_back
#define pof pop_front
#define fir first
#define sec second
#define res resize
#define ins insert
#define era erase
#define RE return 0
//ios::sync_with_stdio(false);
//std::cin.tie(0);
//<< setprecision(20)
const int mod=(int)1000000007;
const llint big=(llint)(2.19e16)+1;
const long double pai=3.141592653589793238462643383279502884197;
const long double ena=2.71828182845904523536;
const long double eps=1e-7;
template <class T,class U>bool mineq(T& a,U b){if(a>b){a=b;return true;}return false;}
template <class T,class U>bool maxeq(T& a,U b){if(a<b){a=b;return true;}return false;}
template <class T> void soun(T& ar)
{sort(ar.begin(),ar.end());ar.erase(unique(ar.begin(),ar.end()),ar.end());}
llint gcd(llint a,llint b){if(a%b==0){return b;}else{return gcd(b,a%b);}}
llint lcm(llint a,llint b){return a/gcd(a,b) *b;}
template<class T,class U> auto LB(T& ve,U in){return lower_bound(ve.begin(),ve.end(),in);}
template<class T,class U> auto UB(T& ve,U in){return upper_bound(ve.begin(),ve.end(),in);}
template<class T,class U> auto LBI(T& ve,U in){return LB(ve,in)-ve.begin();}
template<class T,class U> auto UBI(T& ve,U in){return UB(ve,in)-ve.begin();}
template<class T> void SO(T& ve){sort(ve.begin(),ve.end());}
template<class T> void REV(T& ve){reverse(ve.begin(),ve.end());}
using pli=pair<llint,int>;
using daic=priority_queue<pli,vector<pli>,greater<pli>>;

template <uint64_t MOD_ = 1000000007>
class mint_base
{
public:
	static constexpr auto MOD = MOD_;
	static_assert(!(MOD <= 2), "MOD cannot be below 2.");
	static_assert(MOD <= (0xFFFFFFFFFFFFFFFF / 2), "MOD is too big");//加算してオーバーフローしない
	static_assert(MOD <= 0xFFFFFFFF, "MOD is too big");//乗算してオーバーフローしない
	constexpr mint_base<MOD> operator+(const mint_base<MOD> &other)const noexcept
	{auto v = *this;return v += other;}
	constexpr mint_base<MOD> operator-(const mint_base<MOD> &other)const noexcept
	{auto v = *this;return v -= other;}
	constexpr mint_base<MOD> operator*(const mint_base<MOD> &other)const noexcept
	{auto v = *this;return v *= other;}
	constexpr mint_base<MOD>& operator+=(const mint_base<MOD> &other) noexcept
	{a += other.a;if (MOD <= a) { a -= MOD; };return *this;}
	constexpr mint_base<MOD>& operator-=(const mint_base<MOD> &other) noexcept
	{if (a >= other.a) {a -= other.a;}else {a = (a + MOD) - other.a;}return *this;}
	constexpr mint_base<MOD>& operator*=(const mint_base<MOD> &other) noexcept
	{a *= other.a;a %= MOD;return *this;}
	constexpr mint_base<MOD> operator+()const noexcept { return *this; }
	constexpr mint_base<MOD> operator-()const noexcept
	{return{ MOD - a, mod_value_tag{} };}
	constexpr mint_base<MOD>& operator++() noexcept
	{if (MOD <= ++a) { a = 0; };return *this;}
	constexpr mint_base<MOD>& operator--() noexcept
	{if (a <= 0) { a = MOD; };--a;return *this;}
	constexpr mint_base<MOD> operator++(int) noexcept
	{auto tmp = *this;++*this;return tmp;}
	constexpr mint_base<MOD> operator--(int) noexcept
	{auto tmp = *this;--*this;return tmp;}
	constexpr mint_base<MOD>& operator=(const mint_base<MOD> &other) noexcept
	{a = other.a;return *this;}
	constexpr operator uint64_t()const noexcept
	{return a;}
	constexpr explicit operator unsigned()const noexcept
	{return (unsigned)a;}
	static constexpr uint64_t getmod() noexcept
	{return MOD;}
	constexpr mint_base(uint64_t a_) noexcept :a(a_ % MOD) {}
	constexpr mint_base()noexcept : a(0) {}
	struct mod_value_tag {};
	constexpr mint_base(uint64_t a_, mod_value_tag) :a(a_) {}
private:
	uint64_t a;
};
//mint_base型のstreamへの出力
template<uint64_t MOD> std::ostream& operator<<(std::ostream& os, mint_base<MOD> i)
{os << (uint64_t)i;return os;}
//mint_base型のstreamからの入力
template<uint64_t MOD> std::istream& operator >> (std::istream& is, mint_base<MOD>& i)
{uint64_t tmp;is >> tmp;i = tmp;return is;}

int main(void){
	static mint_base<> niko[10010][10010];
	niko[0][0]=1;
	mint_base<> n;
	llint k,i,j,h;cin>>n>>k;
	for(i=0;i<k+5;i++){
		for(j=0;j<=i;j++){
			niko[i+1][j]+=niko[i][j];
			niko[i+1][j+1]+=niko[i][j];
		}
	}
	//二項係数
	mint_base<>bel[10010];
	bel[0]=1;
	for(i=1;i<=k;i++){
		for(j=0;j<i;j++){bel[i]+=bel[j]*niko[i+1][j];}
		mint_base<> bgen=i+1,g=1;
		for(h=0;h<30;h++){
			if((mod-2)&(1<<h)){g*=bgen;}
			bgen*=bgen;
		}
		bel[i]*=(mod-g);
	}
	cerr<<bel[26]*mint_base<>(6)<<endl;
	mint_base<> rui[10010];rui[0]=1;
	n+=1;
	for(i=1;i<=10005;i++){rui[i]=rui[i-1]*n;}
	mint_base<> ans=0;
	for(i=0;i<=k;i++){
		ans+=niko[k+1][i]*bel[i]*rui[k+1-i];
	}
	mint_base<> bgen=k+1,g=1;
	for(h=0;h<30;h++){
		if((mod-2)&(1<<h)){g*=bgen;}
		bgen*=bgen;
	}
	cout<<ans*g<<endl;
	RE;
}