#include <bits/stdc++.h>

using i64 = long long;

constexpr int P = 1e9 + 7;

template <typename T>
T expow(T a, T b) {
	T res = 1 % P;
	for (; b; b >>= 1) {
		if (b & 1) res = 1ll * res * a % P;
		a = 1ll * a * a % P;
	}
	return res;
}

template <typename T> T read() {
	T sum = 0, fl = 1;
	int ch = getchar();
	for (; !isdigit(ch); ch = getchar()) { if (ch == '-') fl = -1; }
	for (; isdigit(ch); ch = getchar()) sum = sum * 10 + ch - '0';
	return sum * fl;
}

template <typename T> void write(T x) {
	if (x < 0) { x = -x; putchar('-'); }
	if (x > 9) write(x / 10);
	putchar(x % 10 + '0');
}

/* with unlocked: only available on Linux platform */

// template <typename T> T read() {
// 	T sum = 0, fl = 1;
// 	int ch = getchar_unlocked();
// 	for (; !isdigit(ch); ch = getchar_unlocked()) { if (ch == '-') fl = -1; }
// 	for (; isdigit(ch); ch = getchar_unlocked()) sum = sum * 10 + ch - '0';
// 	return sum * fl;
// }

// template <typename T> void write(T x) {
// 	if (x < 0) { x = -x; putchar_unlocked('-'); }
// 	if (x > 9) write(x / 10);
// 	putchar_unlocked(x % 10 + '0');
// }

int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);

	int n = read<int>(), k = read<int>();
	i64 res = n * (expow<i64>(n, k) + P - expow<i64>(n + 1, k)) % P;
	write<i64>(res);
	return 0;
}