#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <unordered_map>
#include <chrono>
#include <random>
#include <functional>
#include <utility>
#include <cassert>
#pragma GCC optimize("O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma comment(linker, "STACK:36777216")
using namespace std;
using i64 = int64_t;
constexpr i64 MOD = 1e9 + 7;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
using vi = vector<i64>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using ii = pair<i64, i64>;

i64 fact[202020];
i64 factinv[202020];
i64 Ber[10001];

i64 modpow(i64 a, i64 n) {
    if (n == 0) return 1;
    if (n % 2 == 0) {
        i64 t = modpow(a, n / 2);
        return t * t % MOD;
    }
    return a * modpow(a, n - 1) % MOD;
}

i64 comb(int n, int r);

void make() {
    fact[0] = 1;
    for (int i = 1; i < 202020; i++) {
        fact[i] = fact[i - 1] * i % MOD;
    }
    for (int i = 0; i < 202020; i++) {
        factinv[i] = modpow(fact[i], MOD - 2);
        assert(fact[i] * factinv[i] % MOD == 1);
    }
    
    Ber[0] = 1;
    for (int i = 1; i < 10001; i++) {
        i64 tmp = 0;
        for (int j = 0; j < i; j++) {
            tmp += comb(i + 1, j) * Ber[j];
            tmp %= MOD;
        }
        Ber[i] = -1 * modpow(i + 1, MOD - 2) * tmp % MOD;
    }
}

i64 comb(int n, int r) {
    if (n < 0 || r < 0 || r > n) return 0;
    return fact[n] * factinv[r] % MOD * factinv[n - r] % MOD;
}

int main() {
    make();
    i64 ans = 0;
    i64 n, k;
    cin >> n >> k;
    for (int j = 0; j <= k; j++) {
        ans += comb(k + 1, j) * Ber[j] % MOD * modpow((n + 1) % MOD, k + 1 - j) % MOD;
        ans %= MOD;
    }
    ans *= modpow(k + 1, MOD - 2);
    ans %= MOD;
    cout << (ans + MOD) % MOD << endl;
}