#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define INF 1000000000
#define mod 1000000007
using ll=long long;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    ll c[2];
    c[0]=1,c[1]=0;

    ll p,k;cin>>p>>k;

    rep(i,k){
        ll d[2]={};
        d[0]+=c[0];d[0]%=mod;// 0->0 (+)
        d[0]+=c[1];d[0]%=mod;// 1~p-1->0 (+)
        d[1]+=c[1]*(p-1)%mod;d[1]%=mod;
        d[1]+=c[0]*(p-1)%mod;d[1]%=mod;

        d[0]+=c[1];d[0]%=mod;
        d[0]+=c[0]*p%mod;d[0]%=mod;
        d[1]+=c[1]*(p-1)%mod;d[1]%=mod;
        swap(c,d);
        // debug(c);
    }
    cout<<c[0]<<endl;
    return 0;
}