#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
#define rep(i,n) for(int i = 0; i < (int)n; i++)
using ll = long long;
using mint = modint998244353;
constexpr int MAX = 3e5;

mint fac[MAX], finv[MAX];

void combinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  for (int i = 2; i < MAX; i++){
    fac[i] = fac[i-1] * mint(i);
    finv[i] = finv[i-1] * mint(i).inv();
  }
}

mint comb(int n, int k){
  if (n < k) return 0;
  if (n < 0 || k < 0) return 0;
  return fac[n] * finv[k] * finv[n-k];
}

int main(){
  combinit();
  int n, k;
  cin >> n >> k;
  mint ans = 0;
  for(int i = 1; i <= n-1; i++) ans += mint(i).pow(k)*comb(n-1,i);
  cout << ans.val() << endl;
  return 0;
}