#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#define popcount __builtin_popcount
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;
const ll MOD=1e9+7;
ll powmod(ll a, ll k){
    ll ap=a, ans=1;
    while(k){
        if(k&1){
            ans*=ap;
            ans%=MOD;
        }
        ap=ap*ap;
        ap%=MOD;
        k>>=1;
    }
    return ans;
}
ll inv(ll a){
	return powmod(a, MOD-2);
}
ll f[20001], invf[20001];
void fac(int n){
    f[0]=1;
    for(ll i=1; i<=n; i++) f[i]=f[i-1]*i%MOD;
    invf[n]=inv(f[n]);
    for(ll i=n-1; i>=0; i--) invf[i]=invf[i+1]*(i+1)%MOD;
}
ll comb(int x, int y){
    if(!(0<=y && y<=x)) return 0;
    return f[x]*invf[y]%MOD*invf[x-y]%MOD;
}
int main()
{
    ll n, k; cin>>n>>k;
    fac(k+1);
    ll b[10010]={};
    ll v[10010];
    for(ll i=1; i<=k+1; i++) v[i]=inv(i);
    b[0]=1;
    for(int i=1; i<=k; i++){
        if(i>2 && i%2==1) continue;
        for(int j=0; j<i; j++) (b[i]+=comb(i+1, j)*b[j])%=MOD;
        b[i]=(MOD-b[i]*v[i+1]%MOD)%MOD;
    }
    ll ans=0;
    n=(n+1)%MOD;
    for(int i=0; i<=k; i++){
        (ans+=comb(k+1, i)*b[i]%MOD*powmod(n, k+1-i))%=MOD;
    }
    ans=ans*v[k+1]%MOD;
    cout<<ans<<endl;
    return 0;
}