#include <iostream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <cassert>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <bitset>
#include <string>
#include <algorithm>
#include <utility>
#define llint long long
#define inf 1e18
#define rep(x, s, t) for(llint (x) = (s); (x) < (t); (x)++)
#define Rep(x, s, t) for(llint (x) = (s); (x) <= (t); (x)++)
#define chmin(x, y) (x) = min((x), (y))
#define chmax(x, y) (x) = max((x), (y))
#define mod 1000000007

using namespace std;
typedef pair<llint, llint> P;

llint p, k;
llint dp[1000005][2];


int main(void)
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> p >> k;
	
	dp[0][0] = 1;
	for(int i = 0; i < k; i++){
		for(int j = 0; j < 2; j++){
			dp[i+1][0] += dp[i][j], dp[i+1][0] %= mod;
			dp[i+1][1] += dp[i][j] * (p-1) % mod, dp[i+1][1] %= mod;
			
			if(j == 0) dp[i+1][0] += dp[i][j] * p % mod, dp[i+1][0] %= mod;
			else{
				dp[i+1][0] += dp[i][j], dp[i+1][0] %= mod;
				dp[i+1][1] += dp[i][j] * (p-1) % mod, dp[i+1][1] %= mod;
			}
		}
	}
	cout << dp[k][0] << endl;
	
	return 0;
}