#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
    int n, k;
    cin >> n >> k;
    vector<vector<mint>> dp(k+1, vector<mint>(n+1));
    dp[0][0] = 1;
    rep(i,k){
        for(int j=0;j<=n;j++){
            if(j+1<=n){
                dp[i+1][j+1] += dp[i][j]*(n-j);
            }
            if(j-1>=0){
                dp[i+1][j-1] += dp[i][j]*j;
            }
        }
    } 
    mint ans = 0;
    mint inv = mint(mint(n).pow(k)).inv();
    for(int j=0;j<=n;j++){
        if((k-j)%2 || k-j<0) continue;
        int cnt = (k-j)/2;
        dbg(j,cnt, dp[k][j].val());
        ans += (n+cnt)*dp[k][j]*inv;
    }
    cout << ans.val() << endl;
    return 0;
}