#include <bits/stdc++.h>
using namespace std;
const int Maxk = 5005;
const int md = 1e9 + 7;
int n, k, m;
long long dp[Maxk][Maxk];
long long fpow(int num) {
  long long rez = 1;
  if (num == 0) return rez;
  rez = fpow(num / 2);
  rez = (rez * rez) % md;
  if (num & 1) rez = (rez * 2) % md;
  return rez;
}
int main() {
  scanf("%d%d", &n, &k);
  m = min(n, k);
  dp[0][m] = fpow(n - m);
  for (int j = m - 1; j >= 0; j--) {
    dp[0][j] = (dp[0][j + 1] * 2) % md;
  }
  for (int i = 1; i <= k; i++) {
    for (int j = 0; j <= m; j++) {
      dp[i][j] = (j * dp[i - 1][j] + (n - j) * dp[i - 1][j + 1]) % md;
    }
  }
  printf("%d\n", dp[k][0]);
  return 0;
}
