#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>
#include <utility>
#include <functional>
#include <time.h>
#include <stack>
#include <array>
#include <list>
#define popcount __builtin_popcount
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;
const ll MOD=1e9+7;
int main()
{
	ll dp[1000010][2]={};
	dp[0][0]=1;
	ll p; int k; cin>>p>>k;
	for(int i=1; i<=k; i++){
		dp[i][0]=(dp[i-1][0]+dp[i-1][1]*(p-1))%MOD;
		(dp[i][0]+=dp[i-1][0]*p+dp[i-1][1]*(p-1))%=MOD;
		dp[i][1]=(dp[i-1][0]+dp[i-1][1]*(p-1))%MOD;
		(dp[i][1]+=dp[i-1][1]*(p-1))%=MOD;
	}
	cout<<dp[k][0]<<endl;
	return 0;
}